Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman. He created many tools in areas such as electricity, sound recording, and movies. These inventions, including the phonograph, the motion picture camera, and early electric light bulbs, have greatly influenced the modern world. He was one of the first inventors to use science and teamwork in the invention process, working with many researchers and employees. He built the first industrial research laboratory.

Edison grew up in the American Midwest. Early in his career, he worked as a telegraph operator, which led to some of his earliest inventions. In 1876, he opened his first laboratory in Menlo Park, New Jersey, where many of his early inventions were made. He started a business and became wealthy. Edison used his money to support his love for inventing. This included experimental mining operations, the first film studio, and 1,093 U.S. patents.

Early life

Thomas Edison was born in 1847 in Milan, Ohio, but moved to Port Huron, Michigan, in 1854 when his family relocated there. He was the seventh child and the youngest of Samuel Ogden Edison Jr. (born in 1804 in Marshalltown, Nova Scotia) and Nancy Matthews Elliott (born in 1810 in Chenango County, New York). His family’s background was Dutch, tracing back to New Jersey.

Edison’s great-grandfather, John Edeson, fled New Jersey for Nova Scotia in 1784. The family moved to Middlesex County, Upper Canada, around 1811. His grandfather, Capt. Samuel Edison Sr., served in the 1st Middlesex Militia during the War of 1812. His father, Samuel Edison Jr., later moved to Vienna, Ontario, but left for Ohio after his involvement in the Rebellion of 1837.

Edison’s mother, a former teacher, taught him to read, write, and do arithmetic. He attended school for only a few months but learned most things by reading on his own. A book titled A School Compendium of Natural and Experimental Philosophy, given to him by his mother, inspired his interest in electricity. His parents also owned books by Thomas Paine, which influenced Edison’s thinking throughout his life.

At age 12, Edison began losing his hearing. Historian Paul Israel believed this was caused by scarlet fever during childhood and untreated ear infections. Edison later made up stories about why he lost his hearing. He was completely deaf in one ear and could barely hear in the other. As an adult, he listened to music or piano by clamping his teeth into the wood to feel sound waves through his skull. He believed his hearing loss helped him focus better on his work.

Edison started his career as a newspaper seller, selling papers, candy, and vegetables on trains between Port Huron and Detroit. By age 13, he earned $50 a week, most of which he used to buy equipment for electrical and chemical experiments. He also founded a newspaper called the Grand Trunk Herald, which he sold with his other papers. The newspaper had 24 issues and covered local news. Five hundred people signed up for the paper, and Edison hired at least two assistants. He kept a frame with the first issue of the Grand Trunk Herald in his home until his death.

In 1862, at age 15, Edison saved a child from a runaway train. The child’s father was so grateful that he trained Edison to become a telegraph operator. Edison worked as a telegrapher in a local store before moving to Stratford Junction, Ontario, where he worked as a night telegrapher for the Grand Trunk Railway. While working, he studied the properties of substances, conducted chemical experiments, and slept during his shifts. This led to a near train collision, after which he resigned from his job.

Telegraphy

From 1863 to 1869, Edison held night shift telegraph jobs in Ontario, Michigan, Kentucky, Ohio, and Massachusetts. As an employee of Western Union, he worked on the Associated Press bureau news wire. In Cincinnati, he lived with Ezra Gilliland, a friend he kept for 25 years. He joined the National Telegraph Union and wrote for their magazine. In his free time, Edison experimented and studied Spanish. He was known among young telegraph operators for being intelligent and trying new ideas, though his experiments sometimes disrupted his work.

In Boston, from 1867 to 1869, Edison earned money by inventing a stock ticker for local customers. However, he lost the income when he expanded the idea to New York without approval. His first patent, for the electric vote recorder (U.S. patent 90,646), was granted on June 1, 1869.

Edison moved to New York City in 1869. Franklin Leonard Pope, a fellow telegrapher, helped the poor young Edison by letting him live and work in the basement of his home in Elizabeth, New Jersey, while Edison worked for Samuel Laws at the Gold Indicator Company. Pope and Edison started their own company in October 1869, working as electrical engineers. Edison attracted wealthy investors, who allowed them to hire 50 employees and open a larger shop in Newark, New Jersey. The company earned money by renting telegraph lines. To win business, they built machines that recorded telegraphs and typewriters that printed directly to wires. Edison closely managed his employees’ work and tested many experiments.

Edison took a chemistry course at The Cooper Union for the Advancement of Science and Art to support his work on a new telegraph system with Charles Batchelor. This was the only time he enrolled in classes at a higher education institution. At the factory, Edison and Batchelor worked together intensely; their shared notebooks, signed "E&B," show continuous experiments to improve the telegraph.

Edison grew the company to hundreds of employees. In 1874, he received $30,000 ($853,676 in 2025) for inventing the first telegraph that could send four messages at once through one wire. He used the money to invest in the Port Huron street railway, owned by his brother William Pitt. He expanded his business and hired his young nephew and father.

Menlo Park laboratory

In Menlo Park, New Jersey, Edison created the first industrial laboratory focused on creating knowledge and applying it. The laboratory was built in 1876 in Raritan Township, which later became Edison Township in his honor. Funds from the sale of Edison's quadruplex telegraph helped pay for the laboratory. His staff followed his directions closely during research, and he pushed them hard to achieve results. Edison's name appears on 1,093 patents. As the leader of the laboratory, Edison was credited for inventions made by others working under him. He worked long hours and expected others to do the same. This often included 18 hours per day from Monday to Friday and additional work on weekends. One employee described the work as reaching "the limits of human exhaustion." Edison often fought legal battles and used patent lawyers to challenge the intellectual property rights of others.

For Edison, success in business brought attention. He limited public access to the Menlo Park laboratory and controlled how he was portrayed in interviews. He supported the creation of a science journal called Science, which began publishing in 1880. Edison remained anonymous in his role, and the journal initially promoted articles favoring him. He stopped supporting the journal in 1883 because it was not profitable. Alexander Graham Bell later took over the journal.

Within a little over 10 years, Edison's Menlo Park laboratory grew to cover two city blocks. Edison wanted the lab to have "a stock of almost every conceivable material." In 1887, the lab contained "eight thousand kinds of chemicals, every kind of screw, every size of needle, every kind of cord or wire, hair from many animals, silk in every texture, cocoons, various kinds of hoofs, shark's teeth, deer horns, tortoise shell, cork, resin, varnish, ostrich feathers, a peacock's tail, jet, amber, rubber, all ores," and many other items.

In 1876, Edison worked to improve the microphone for telephones by developing a carbon microphone. This device used two metal plates separated by carbon granules that changed resistance based on sound wave pressure.

In 1877, Edison and his supporters at Western Union aimed to compete with Alexander Graham Bell's telephone technology. Edison believed Bell's microphone, designed by Emile Berliner, was a weakness. He tested many designs to find the best sound quality for his deaf ears. His idea was to use a stronger current that changed with sound waves. Sound waves pressed a carbon pad, altering the circuit's resistance. After testing 150 materials, Edison found parchment and tinfoil best for the diaphragm, and specially coated rubber worked as the semiconductor.

In 1878, David Edward Hughes published a paper on loose-contact carbon microphones. He claimed to discover the semiconductor effect and introduced the Hughes Telephone. This upset Edison and caused controversy, especially since Hughes acknowledged advice from one of Edison's colleagues.

Edison's first widely recognized invention was the phonograph in 1877. He promoted the invention through interviews and public demonstrations. People were surprised by the phonograph, which seemed almost magical. Edison became known as "The Wizard of Menlo Park." As he aged, he disliked being called a genius and emphasized "one percent inspiration and 99 percent perspiration."

The first phonograph recorded sound on tinfoil wrapped around a grooved cylinder. Though the sound quality was poor and recordings could only be played a few times, the phonograph made Edison famous. Joseph Henry, president of the National Academy of Sciences, called Edison "the most ingenious inventor in this country… or in any other." In 1878, Edison demonstrated the phonograph before the academy. Though he patented the phonograph in 1878, he did not develop it further until Bell, Chichester Bell, and Charles Tainter created a similar device in the 1880s using wax-coated cardboard cylinders.

In 1887, the Edison Phonograph Company was formed to compete with Bell. Gilliland, who had worked for Bell, joined Edison's company. However, the venture ran out of money and required funding from an investor named Jesse Lippincott. Lippincott made secret deals with Edison, Gilliland, and Bell to create a monopoly but hid his role. When Edison discovered the plan, he was angry, and Gilliland left for Europe, ending their friendship. After five years of legal battles, Edison gained full control of the company. This caused conflicts with other inventors who had supported Edison.

Edison struggled to make the phonograph practical for years. The main problem was finding a durable recording material that would not damage the phonograph's needle. He tried making talking dolls with a miniature phonograph inside, but the system often failed during production. The project was shut down in 1890. Edison believed the phonograph could improve business and change the role of secretaries. However, by 1899, Edison's company adapted to market demands and produced a low-cost phonograph for entertainment. In 1900, the phonograph sold for $10, and buyers could choose from 3,000 musical records made by Edison's 1,000 employees. Experts supervised the quality of the records. Edison had no musical training, could not read sheet music, and was mostly deaf. He personally approved every artist based on what he thought sounded good and kept their names hidden from the music.

The rise of radio hurt phonograph sales. Edison's business sold 90% fewer records in 1921 compared to 1920. From 1922 to 1926, radio sales increased by 843%. Younger managers, including Edison's son Charles, tried to convince him to enter the radio business or use new advertising methods. Instead, Edison focused on removing employees who did not meet his standards.

Edison invented a highly sensitive device called the tasimeter, which measured infrared radiation. He created it to study the heat from the solar corona during a total solar eclipse on July 29, 1878.

Electric light

In 1878, Edison started working on an electrical lighting system he could use in a large-scale business, hoping it would compete with gas and oil lighting. A strong, low-resistance incandescent lamp was essential for his system. Many inventors had created incandescent lamps before Edison, but these early bulbs had problems, such as short lifespans and needing high electric currents, which made them hard to use widely. Edison first tried using a cardboard filament covered in lampblack, but it burned out too quickly. He then tested different grasses and canes, like hemp and palmetto, before choosing bamboo as the best filament.

Edison saw lighting as a complete system. He conducted experiments, did market research with Grosvenor Lowrey, connected with powerful investors, studied electric generators, planned power distribution, and gave public speeches to promote his work. In 1878, he formed the Edison Electric Light Company in New York City with financiers like J. P. Morgan, Spencer Trask, and members of the Vanderbilt family.

Edison kept improving his design. On November 4, 1879, he applied for a U.S. patent (223,898) for an electric lamp using a carbon filament coiled and connected to platina wires. The patent described methods to create the filament, such as using cotton thread, wood splints, or paper. Months later, Edison and Batchleor found that a carbonized bamboo filament could last over 1,200 hours. This high-resistance filament led Edison to choose the 110V power standard in the U.S., which was higher than what competitors used. Employees helped test filaments, make glass bulbs, and create vacuums for the filament to glow. By February 1880, people visited the "Village of Light" in Menlo Park to see his work.

Edison worked to prevent blackening inside bulbs caused by carbon particles from the hot filament. This led to the creation of Edison effect bulbs. His 1883 patent for voltage regulation was the first U.S. patent for an electronic device because it used the Edison effect in an active component. The Edison Effect later helped design vacuum tubes.

In 1878, Edison hired Francis Robbins Upton, a former student of Hermann von Helmholtz. Upton received 5% of company profits and later became general manager after leading research on electric lighting. He helped write Edison’s speeches and made hiring decisions. John Ott worked for Edison, making mechanical improvements and conducting experiments. Both Upton and Ott agreed to credit Edison for most patents, though Ott was solely credited for some. Ott’s testimony supported Edison’s patent claims. John Ott’s brother, Fred, worked as an experimental assistant for 57 years.

Henry Villard, president of the Oregon Railroad and Navigation Company, attended Edison’s 1879 demonstration. Impressed, he asked Edison to install his lighting system on the Columbia. Edison agreed, and by May 1880, the Columbia’s new lighting system was completed. The Columbia became Edison’s first commercial use of the incandescent bulb. The Edison equipment was removed from the Columbia in 1895.

Villard later helped fund an electrically powered train built on a custom track by Edison’s company. The train worked, and some technology was patented, but Edison focused on bulbs instead of continuing the train project.

Edison’s incandescent bulb became popular in Europe. He sent engineers to promote his system in London and across Europe.

On September 4, 1882, Edison turned on his electrical lighting system for 946 customers in Manhattan. Many people did not notice the lights at first because they were so steady and similar to gas lighting. The Boston Globe reported on the event.

In 1883, the U.S. patent office ruled that Edison’s filament improvement process was based on Sawyer’s method and was invalid. Edison’s company revised their process until 1889, when a judge ruled their new patent valid. To avoid a legal battle with Joseph Swan, who held a similar British patent, Edison and Swan formed a joint company called Ediswan to market the invention in Britain. Westinghouse, which owned Sawyer’s patent, took a large share of the bulb market by 1889.

After creating a commercially viable bulb on October 21, 1879, Edison developed an electric utility to compete with gas lighting. To show progress, he hosted a board meeting illuminated by his system. On December 17, 1880, he founded the Edison Illuminating Company and patented an electricity distribution system in the 1880s.

The amount of copper wire needed for his system was very large. To reduce copper use, Edison invented a three-prong wire system.

To grow his influence in New York and secure rights for underground electric lines, Edison’s company opened a second office on 65th Avenue. The Edison Machine Works and Edison Electric Tube Company opened in New York by the end of the year. Edison paid his workers more than other companies in the 1880s. Before commercializing power distribution, Edison needed a way to measure customer power use. He invented a device with zinc plates that collected current from customers. Zinc from the solution would build up on the plates, and their weight was measured monthly to bill customers.

In January 1882, Edison turned on the first steam-generating power station in London. On September 4, 1882, he activated his 600 kW steam-powered generating station in New York City, providing 110 volts direct current (DC). Subscriptions grew to 508 customers with 10,164 lamps.

As Edison expanded his DC power system, he faced competition from companies using alternating current (AC). AC arc lighting systems for streets and large spaces had grown in the U.S. By the 1880s, transformers developed in Europe and by Westinghouse Electric in the U.S. allowed AC to be sent long distances over thinner wires. At the destination, voltage could be reduced for distribution to users. This made AC useful for street lighting and small businesses.

Mining

Starting in the late 1870s, Edison became interested in mining. High-quality iron ore was hard to find on the east coast, which made it expensive because ore was usually brought from the Midwest. Edison tried to solve this by mining lower-quality ore and beach sand. Others had tried using magnets to separate iron from other metals, but none had done it successfully or made money from it.

In 1880, the Edison Ore Milling Company began by removing iron from beach sand. Edison promised to deliver hundreds of tons of ore each month to customers, but after three years, the operation closed, and only one customer had received their ore. William Kennedy Dickson and John Birkinbine led the project. Batchelor and Insull provided some money, and Edison used most of the funding from his own savings.

This first mining effort did not completely fail. Edison was able to license some of the technology to other iron producers. The West Orange team kept improving the technology over the years. Edison later bought a mine in Bechtelsville, Pennsylvania. Birkinbine wanted to use the mine to show others how the technology worked, but Edison wanted to control the mining industry himself. Birkinbine was fired in 1890.

Edison bought several mines in the eastern United States and started building a new central mining operation in Ogdensburg, New Jersey. The new process used rollers and crushers to break rocks as large as five tons. To get the rocks, Edison bought the largest steam shovel in America. One special part of Edison’s system was electric rollers that rotated very quickly. The rollers’ gears released at the right moment to crush the rocks using their movement. Edison used automation instead of manual labor, allowing rocks to move through the facility on conveyor belts, sieves, and more rollers. The smaller pieces of ore were sent through a system of 480 electromagnets to separate iron from other materials.

Customers avoided iron with high phosphorus levels because it made the Bessemer process less effective. Edison’s system used an air-powered method to remove phosphorus, taking advantage of its lighter weight. Economic reasons also required iron ore to be mixed into briquettes for transport to steel mills. Edison automated this process, which he was proud of because it took only two hours. His goal was to eliminate the need for humans to handle the iron directly. However, the mine continued to lose money.

In 1893, the United States faced a serious economic downturn. High costs from mining investments, falling iron prices, and the expensive lifestyle of Edison’s wife and children put him at risk of going bankrupt. He was also unwell due to his diabetes. He borrowed money from his father-in-law to stay afloat.

In 1901, Edison visited an industrial show in Sudbury, Ontario, Canada, and noticed nickel and cobalt deposits that could be useful for electrical equipment. He returned as a mining expert and is credited with discovering the Falconbridge ore body. His attempts to mine the area failed, and he gave up his claim in 1903.

Despite the mining failures, Edison used materials from the process to make Portland cement. Manufacturing iron ore created a lot of waste sand, which he sold to cement makers. In 1899, he started the Edison Portland Cement Company to produce his own cement and improve its manufacturing process.

Making Portland cement requires baking limestone and other minerals at high temperatures. Edison created a new system that used long, horizontal kilns 150 feet long. This allowed the cement to reach the same quality by cooking it longer at a lower temperature, which saved coal and reduced the need for manual labor. Edison reused materials from the Ogden mine to build his system. He also sold his cement-making method to other companies and earned money from royalties until the 1920s.

Working machines in dusty environments caused many problems. Dynamos, which generate electricity, were especially difficult to protect from dust because they needed to release heat. Edison invented a fan cooling system to bring in fresh air to cool the dynamos while keeping dust out.

In 1901, Edison tried to use his cement business to start a low-cost housing project. He aimed to build small towns where everyone could afford a home. He designed a system to cast entire three-story houses from cement in one mold. He used this method to build homes for workers and promoted it publicly, but it did not generate enough interest to continue the project.

West Orange

In the spring of 1886, the first labor strike against Thomas Edison took place. It was led by D.J. O'Dare of the Edison Tube Works. At that time, workers in New York City usually worked nine hours a day, and Edison’s employees were among the highest-paid in the city. However, they did not receive extra pay for overtime work. The strike aimed to demand higher wages, overtime pay, and the right to form a union. Edison and other managers refused to allow unionization, fearing it would reduce their control over the workplace. By the end of 1886, Edison’s manufacturing plants in New York City were closed. Instead, the Edison United Manufacturing Company opened a new factory in Schenectady, New York. Citizens of Schenectady helped pay 16% of the cost for the real estate to attract Edison’s business to their town.

Samuel Insull began working for Edison in 1881 as a secretary. He had previously worked at Vanity Fair. Insull became a close friend and trusted assistant to Edison. Later, when Edison’s wife, Mary, was dying, Insull helped the family with arrangements. Like all of Edison’s employees, Insull worked hard. When the Edison United Manufacturing Company opened, he was one of two managers.

In December 1886, Edison was unable to leave his home due to an illness called pleurisy. He recovered but needed emergency surgery in May 1887 to treat abscesses near his ear. He had similar surgeries in 1906 and 1908.

By 1887, Edison felt he needed more space than Menlo Park provided. He assigned Batchelor to build a new laboratory complex in West Orange, New Jersey. When completed, the new lab was more than ten times the size of the old one.

In December 1914, a fire killed one worker and destroyed thirteen buildings, causing $1.5 million in damage. The phonograph factory was destroyed. Edison remained optimistic and ordered all buildings rebuilt with the latest technology. By January 1915, production had resumed. The fire’s effects were less severe because the factory regularly practiced fire drills.

In 1921, after President Warren G. Harding was inaugurated, the United States entered a recession. Edison had experience managing businesses during economic downturns and had seen friends go bankrupt. He fired thousands of employees, including executives. By fall 1921, the economy improved, and business returned. However, Edison narrowly avoided bankruptcy.

Edison learned about X-rays in 1896, after physicist Wilhelm Röntgen discovered them. He was sent a photo of Röntgen’s hands showing visible bones. Edison was excited by the technology and worked to develop an improved X-ray system using better glass and more electricity. During experiments, he discovered that X-ray images appear clearer on calcium tungstate screens. He shared this finding with Lord Kelvin.

The basic design of Edison’s fluoroscope is still used today. However, Edison stopped the project after nearly losing his eyesight and seriously injuring his assistants, Clarence Dally and Charles Dally. In 1903, Edison said, “Don’t talk to me about X-rays, I am afraid of them.” The brothers often tested the fluoroscope on themselves. Clarence Dally died at 39 from injuries related to X-ray exposure, including cancer.

In the late 1890s, Edison worked on creating a lighter, more efficient rechargeable battery. He aimed to power phonographs but later focused on batteries for electric cars. At the time, lead-acid batteries were common but inefficient and protected by patents. In 1900, Edison decided to develop an alkaline battery for electric cars. His lab tested 10,000 combinations of materials before settling on a nickel-iron design.

Waldemar Jungner was also working on a similar battery design. Edison and Jungner had a legal dispute over patents as Edison tried to commercialize his battery. Edison received U.S. and European patents for his nickel-iron battery in 1901 and started the Edison Storage Battery Company. In 1904, Edison worried about losing the patent battle and asked President Theodore Roosevelt to intervene. Roosevelt agreed, but the patent office still denied Edison’s claim.

By 1904, the Edison Storage Battery Company employed 450 workers. The first batteries produced were for electric cars. However, a recall was issued because the batteries lost power after repeated use.

Henry Ford first met Edison in 1896 while working for Edison Illuminating Company. Edison supported Ford’s early experiments with automobiles, and Ford left in 1899 to start his own car company. By 1908, gas-powered cars like Ford’s Model T became popular. Edison did not produce a mature battery until 1910: a durable nickel-iron battery with lye as the electrolyte. However, the battery was not successful, as electric cars were declining, and lead-acid batteries became standard for gas-powered cars. Ford still supported Edison and lent him $1.1 million (equivalent to $35.4 million in 2025) for further research, but Edison could not develop a competitive battery.

Motion pictures

In 1888, Thomas Edison and William Kennedy Laurie Dickson, a photographer who worked for Edison, began creating a camera to "do for the eye what the phonograph does for the ear." They first tried using microphotographs on a cylinder. Edison focused on the parts of the camera that used electricity and machines, while Dickson led the work on the optical parts and film. In 1897, Edison received a patent for a motion picture camera called the "Kinetograph." Much of the credit for this invention belongs to Dickson.

A prototype film camera was built using 19mm film with round images. The first successful tests with this camera were shown publicly on May 20, 1891, in a simple viewer.

Edison aimed for a bigger goal than just a motion picture camera. He wanted a device called a "kinetophonograph" to record both moving pictures and sound with synchronized playback. In 1890, Dickson made the first film with sound, starring himself. However, keeping sound and video in sync was very difficult, so Edison stopped developing this technology commercially.

In 1891, Edison built a Kinetoscope, also called a peep-hole viewer. This device was placed in penny arcades, where people could watch short films. The Kinetograph and Kinetoscope were first shown publicly on May 20, 1891.

In the last three months of 1894, an Edison associate sold hundreds of Kinetoscopes in the Netherlands and Italy. In Germany and Austria-Hungary, the Kinetoscope was introduced by a company called Deutsche-österreichische-Edison-Kinetoscop Gesellschaft, founded by Ludwig Stollwerck of a chocolate company in Cologne.

By 1895, Dickson began setting up his own business, separate from Edison. The exact reason for this split is unknown, but it likely involved disagreements between them.

The first Kinetoscopes arrived in Belgium at fairs in early 1895. A Belgian company, Edison's Kinétoscope Français, was founded in Brussels on January 15, 1895, with rights to sell Kinetoscopes in Monaco, France, and French colonies. The main investors were Belgian industrialists. On May 14, 1895, another company, Edison's Kinétoscope Belge, was also founded in Brussels. A businessman named Ladislas-Victor Lewitzki, who lived in London but worked in Belgium and France, started this business. He had connections with Leon Gaumont and the American Mutoscope and Biograph Co. In 1898, he became a shareholder of the Biograph and Mutoscope Company in France.

In April 1896, Thomas Armat made a deal with Edison. Edison's company manufactured and sold the Vitascope, a film projector. The Vitascope was advertised as an Edison invention to help sales, but it was actually created by Armat and C. Francis Jenkins. Edison had tried to make his own projector but gave up because the Vitascope was better.

Edison's film studio made nearly 1,200 films. These included short films showing acrobats, parades, and fire calls, such as Fred Ott's Sneeze (1894), The Kiss (1896), The Great Train Robbery (1903), Alice's Adventures in Wonderland (1910), and the first Frankenstein film (1910). Edison let Edwin S. Porter manage the creative side of the movie business. In 1903, Luna Park on Coney Island announced it would kill an elephant named Topsy. Edison's company filmed the event, Electrocuting an Elephant, as alternating current killed the animal.

As the film business grew, competitors often copied and showed each other's films. To protect his films, Edison sent copies of them to the U.S. copyright office on long strips of photographic paper. Many of these paper copies survived longer and in better condition than the actual films from that time.

In 1908, Edison started the Motion Picture Patents Company, a group of nine major film studios (known as the Edison Trust).

In 1913, movies used live actors and bands to add sound. Edison believed his "kinetophone" technology could synchronize recorded sound and motion pictures. At the same time, Leon Gaumont was working on similar technology. Both systems required a skilled projectionist to adjust the video speed for sound playback.

In 1914, Edison fired Porter for unclear reasons. By this time, the technical challenges of silent, black-and-white film had mostly been solved, and storytelling no longer interested Edison. The kinetophone was hard to use and difficult to sell. Edison's movie business began to decline.

Edison said his favorite movie was The Birth of a Nation. He believed "talkies" (films with sound) had ruined movies for him. He said, "There isn't any good acting on the screen. They concentrate on the voice now and have forgotten how to act. I can sense it more than you because I am deaf." His favorite actors were Mary Pickford and Clara Bow.

National security

Because of security issues during World War I, Edison proposed creating a science and industry committee to help the U.S. military with advice and research. He led the Naval Consulting Board in 1915, but he attended few meetings because he was deaf. One of the board’s main tasks was to find a place for the navy to conduct research. Edison wanted the site to be far from Washington, D.C., because he believed too many government officials would slow progress. However, the other board members ignored his suggestion, and he focused instead on experiments with military technology.

At the start of the war, Edison tried several methods to improve submarine detection, but the Navy did not adopt them. He allowed Miller Hutchinson to promote his battery technology as a safer alternative to lead batteries on submarines. A submarine crew had suffered serious injuries when a lead battery leaked sulfuric acid, mixing with seawater to create chlorine gas inside the vessel. However, Edison’s nickel-iron batteries leaked hydrogen gas. While this was not a problem in cars, hydrogen gas could be dangerous in submarines. In January 1916, a hydrogen explosion occurred during maintenance on the USS E-2, killing five people. Edison and Hutchinson claimed the explosion was due to operator error, but many naval officials blamed them for overpromoting the battery. This event reduced sales of the battery but did not harm Edison’s reputation with the navy.

In 1915, the United States used 75% of the world’s rubber but produced very little. Edison and other business leaders worried about America’s dependence on foreign rubber supplies. Their concerns grew when the Stevenson Plan was introduced in 1921. Edison, along with Ford and Firestone, funded a laboratory with $75,000 to find a domestic source of rubber.

Edison remained active in the press even as he grew older. For his 80th birthday, he gave tours of his experimental garden and shared research on plants that could produce rubber. After testing 17,000 plant samples, he found that the Goldenrod plant, Solidago leavenworthii, could be bred to produce 12% latex. Edison used a methodical approach to solve problems related to rubber production. He evaluated plants based on their latex content, how easily latex could be extracted, where latex was located in the plant, how quickly the plant grew, and how easy it was to harvest.

Edison’s work with the phonograph business led him to hire chemists to develop coatings for records to prevent wear. He eventually licensed a material called Condensite, made from phenol and formaldehyde. At the start of World War I, the American chemical industry relied heavily on European imports. The war caused a shortage of phenol, which was used to make explosives and aspirin.

Edison responded by producing phenol at his Silver Lake facility using methods developed by his chemists. He built two plants that could make six tons of phenol daily. Production began in early September, just one month after war started in Europe. He also built two plants in Johnstown, Pennsylvania, and Bessemer, Alabama, to produce benzene, replacing supplies previously imported from Germany. Edison manufactured aniline dyes, which had been supplied by German companies. Other wartime products included xylene, p-phenylenediamine, shellac, and pyrax. Shortages during the war made these projects profitable. By mid-1915, Edison’s production capacity was fully used. Though he preferred not to sell phenol for military use, he sold surplus to Bayer, which sent it to Germany.

Final years

Henry Ford, a leader in the car industry, lived a short distance from Edison at his winter home in Fort Myers. They remained friends until Edison's death. From 1914 to 1924, Edison and Ford took yearly motor camping trips. Harvey Firestone and naturalist John Burroughs also joined these trips. The trips helped promote Ford cars, Firestone tires, and Edison's projects at the time. Reporters traveled with them to share news about the trips.

In 1926, at age 79, Edison passed the presidency of Thomas A. Edison, Inc. to Charles.

Edison stayed involved in business until his final years. Just months before his death, the Lackawanna Railroad started electric train service from Hoboken to Montclair, Dover, and Gladstone, New Jersey. The trains used an overhead wire system powered by direct current, a method Edison supported. Despite his poor health, Edison was present when the first electric Multiple-Unit (MU) train left Lackawanna Terminal in Hoboken in September 1930. He operated the train for the first mile through Hoboken yard on its journey to South Orange.

In his final years, Edison continued to chew tobacco daily, and his diabetes worsened. Edison died on October 18, 1931, at Glenmont and was buried on the property.

A test tube containing Edison's last breath is kept as a remembrance at The Henry Ford museum near Detroit. Charles Edison arranged for the test tube to be sent to Ford as a symbol of his father's love for chemistry and friendship with Ford. A plaster death mask and casts of Edison's hands were also created.

Domestic life

On December 25, 1871, at the age of 24, Thomas Edison married Mary Stilwell, who was 16 years old. Mary was born in 1855 and died in 1884. She worked at one of Edison’s shops, and they met two months before their marriage. Together, they had three children:

• Marion Estelle Edison (1873–1965), nicknamed "Dot"
• Thomas Alva Edison Jr. (1876–1935), nicknamed "Dash"
• William Leslie Edison (1878–1937), an inventor who graduated from the Sheffield Scientific School at Yale in 1900.

Edison often spent more time in his laboratory than with his family. He did not provide Mary much companionship, and she was closest to her sister.

Thomas Jr. was sick often as a child, but Edison left his care to Mary. Marion, the oldest daughter, sometimes visited Edison’s laboratory in Menlo Park during her childhood.

Thomas Jr. wanted to be an inventor but struggled with the work. He became involved in untrustworthy and dishonest businesses, including selling products falsely labeled as "The Latest Edison Discovery." This caused problems for Edison’s reputation. To stop the practices, Edison took his son to court and agreed to give him $35 per week (equivalent to $1,254 in 2025) in exchange for not using the Edison name. Thomas Jr. used other names, such as Burton Willard. He later faced challenges with alcoholism and depression. His marriage in 1899 caused scandal for him and his father. In 1931, near the end of his life, Thomas Jr. worked for the Edison company with help from his half-brother, Charles.

When the Edisons moved to New York, they lived near Gramercy Park. After the first few years of their marriage, Edison spent less time with Mary. She enjoyed shopping for clothes and attending social events. By 1882, doctors were worried about Mary’s mental health.

Mary died on August 9, 1884, at the age of 29. The cause of her death is unknown, but it may have been due to a brain tumor or a morphine overdose. At the time, doctors often prescribed morphine to women for various health issues.

In December 1884, Edison met Mina Miller at the World Cotton Centennial. Mina was the daughter of Lewis Miller, an inventor who improved a wheat mower and helped establish the Chautauqua Institution. Mina lived a social life and followed a strict Methodist faith. She was friends with the Gillilands, and Edison met her several times in 1885 while working on a project in Boston. They later traveled together, and Edison proposed to her in September 1884.

On February 24, 1886, at the age of 39, Edison married Mina Miller, who was 20 years old. They had three children:

• Madeleine Edison (1888–1979)
• Charles Edison (1890–1969)
• Theodore Miller Edison (1898–1992)

Marion, the oldest daughter, had difficulty getting along with Mina and moved to Germany in 1894. She returned to the United States in 1924 after divorcing her husband.

In his second marriage, Edison was often absent from his family and left most household responsibilities to Mina and her five maids. One exception was the Fourth of July, when Edison enjoyed fireworks. He made his own fireworks, adding a small amount of TNT to the explosions.

Edison wrote love letters to Mina when he was away for long periods. Madeleine said she had few memories of her father, who was typically only at home once a week during her childhood. She later married John Eyre Sloane.

Theodore was named after Mina’s brother, who died in the Spanish–American War shortly before Mina gave birth. His sister died in November of that year, and his father, Lewis Miller, died in February 1899.

Theodore studied physics at the Massachusetts Institute of Technology (MIT). After working for his brother Charles, Theodore started his own laboratory as an independent inventor.

Charles studied general science at MIT. He took over his father’s business after Edison’s death and later served as Governor of New Jersey from 1941 to 1944.

In 1885, Edison bought 13 acres of land in Fort Myers, Florida, for about $2,750 (equivalent to $98,542 in 2025). He built a home called Seminole Lodge, which later became a winter retreat. The house and guest house were designed in Italianate and Queen Anne architectural styles.

In 1886, Edison purchased a home named Glenmont in Llewellyn Park, West Orange, New Jersey. He sold the home to Mina in 1891.

Edison enjoyed boats, cars, and fishing. He rarely drove but owned several cars for research. He encouraged his son Charles to drive even as a child.

Views

Historian Paul Israel described Edison as a "freethinker." Edison was greatly influenced by Thomas Paine's book The Age of Reason. Edison supported Paine's belief in "scientific deism," explaining, "He has been called an atheist, but atheist he was not. Paine believed in a supreme intelligence, which other people often call a deity." In an October 2, 1910, interview, Edison said:

Edison was accused of being an atheist because of these remarks. Though he avoided public debate, he clarified his views in a private letter:

He also said, "I do not believe in the God of the theologians, but I do not doubt that there is a Supreme Intelligence."

Edison studied and promoted ideas related to panpsychism.

Edison's father was a Democrat who supported the secession of the Confederate States of America. Edison was a lifelong Republican, but he briefly supported Theodore Roosevelt during Roosevelt's third presidential campaign as a Progressive Party candidate. Edison valued the Republican Party's support for industrial capitalism and tariffs.

Edison met several U.S. presidents. He met Rutherford B. Hayes in 1879 to demonstrate the phonograph and met Benjamin Harrison in 1890. In 1921, Edison met President Warren G. Harding during the Firestone and Ford summer caravan. In 1924, Edison met Calvin Coolidge at the president's home in Vermont. In 1928, Edison received the Congressional Gold Medal, and Coolidge used the radio to speak at the ceremony. In 1929, Herbert Hoover met Edison at Seminole Lodge. Ten months later, Hoover traveled with Edison and Ford to Ford's reconstruction of Menlo Park.

Edison supported women's suffrage. In 1915, he said, "Every woman in this country is going to have the vote." Edison signed a statement supporting women's suffrage to counter anti-suffragist writings by Senator James E. Martine. His use of women in factory jobs, such as making brush wires for dynamos, was notable at the time.

Nonviolence was central to Edison's political and moral beliefs. When asked to serve as a naval consultant during World War I, he agreed to work only on defensive weapons. He later said, "I am proud of the fact that I never invented weapons to kill." After a 1911 trip to Europe, Edison criticized "the belligerent nationalism" he observed in many countries.

In May 1922, Edison published a proposal titled A Proposed Amendment to the Federal Reserve Banking System, suggesting a currency backed by goods like gold or silver. The proposal did not gain support and was later abandoned.

Awards

The following is a list of some awards received by Edison during his lifetime:

• In 1878, received an honorary doctorate degree from Union College
• On November 10, 1881, appointed as an Officer in the Legion of Honour
• In 1892, received an award from the Manchester Literary and Philosophical Society
• In 1889, received the John Scott Medal
• In 1899, received the Edward Longstreth Medal from The Franklin Institute
• In 1908, received the John Fritz Medal
• In 1915, received the Franklin Medal from The Franklin Institute
• In 1920, received the Navy Distinguished Service Medal
• In 1923, received the Edison Medal from the American Institute of Electrical Engineers
• In 1927, became a member of the American Philosophical Society
• On May 29, 1928, received the Congressional Gold Medal

Primary sources

• The Thomas A. Edison Papers Digital Edition
• The Papers of Thomas A. Edison, a 9-volume book edition. Each volume can be downloaded for free. Volume 1 (1847–1873) is available online. Volume 2 (1873–1876) is also available online.