Thomas Edison

Edison was born on February 11, 1847, in the canal town of Milan, Ohio, the youngest of the seven children of Samuel and Nancy Edison. When he was seven, his family moved to Port Huron, Michigan, where he lived until he left home at sixteen. He attended school for only a few months; he was taught reading, writing and arithmetic mainly at home by his mother, who had been a teacher, and afterward taught himself extensively, reading in his father’s library.⁠[1][2][1][1][2][2]

In 1859, Edison began selling newspapers, magazines and candy on a branch of the Grand Trunk Railroad that ran between Port Huron and Detroit; at one point he printed a newspaper on the train, and he also conducted chemical experiments in a baggage car. In the stations along the line, he became interested in the telegraph and learned to send and receive messages.⁠[2][2][1][3]

By 1862, Edison had learned enough telegraphy to become an operator in a local telegraph office; from 1863 to 1867 he moved among cities of the American Midwest as an itinerant telegrapher, reading widely, studying and experimenting with telegraph technology, and gradually familiarizing himself with electrical science.⁠[2][2][2]

In 1868, Edison arrived in Boston and began to change from telegrapher to independent inventor. On October 13 of that year, at the age of 21, he executed his first successful U.S. patent application, for an electric vote recorder intended to speed voting in bodies such as Congress; the invention was a commercial failure, and he resolved that in the future he would only invent things the public actually wanted.⁠[1][2][4][1][1]

In 1869, Edison moved to New York and continued inventing telegraph-related devices for major telegraph companies. After expertly repairing a telegraphic gold-price indicator on Wall Street, he was hired to supervise the equipment, and he then developed an improved stock ticker, the “Universal Stock Printer”; he was paid $40,000 for this and related inventions.⁠[1][2][5][1]

In 1871, Edison used this income to set up his first small laboratory and manufacturing shop in Newark, New Jersey, employing experimental machinists to assist in his inventions; over the next five years he mainly developed devices that improved the speed and efficiency of the telegraph, including stock tickers, fire alarms, methods of sending multiple messages simultaneously on one wire, and an electrochemical automatic telegraph. The most important achievement of this period was the quadruplex telegraph, which could send two messages simultaneously in each direction on one wire. He also married Mary Stilwell during this period.⁠[1][2][1][2][2][1]

In 1876, Edison sold all his Newark manufacturing businesses and moved with his family and assistants to the village of Menlo Park, about 25 miles southwest of New York, where he established a freestanding research facility with both a machine shop and laboratories, equipped to work on any invention. He promised a minor invention every ten days and a “big trick” every six months, and proposed to “make invention to order.” This kind of research and development laboratory later became a model for modern research institutions such as Bell Laboratories, and is sometimes called Edison’s greatest invention.⁠[1][2][5][1]

The work at Menlo Park was intense; the normal sixty-hour work week often stretched to eighty hours. Edison led by example, dressing and acting like his employees but working harder than all of them. Many of the young men at the laboratory later took positions in Edison’s electric lighting enterprises; for example, Francis Upton ran the lamp factory, and Charles Clarke became chief engineer of Edison Electric.⁠[6][6][6][6]

Urged by Western Union to develop a transmitter to compete with Alexander Graham Bell’s telephone, Edison invented a principle in which a button of compressed carbon changed its resistance as it was vibrated by sound, a principle used in telephones for about the next century. While working on the telephone in the summer of 1877, he discovered a method of recording sound, and in the late fall of that year he unveiled the tinfoil phonograph, the first machine that could record and reproduce sound; on December 7, he demonstrated it at the New York offices of Scientific American.⁠[2][2][2][1][3]

The phonograph brought Edison international fame. He toured the country with the tinfoil phonograph and, in April 1878, was invited to the White House to demonstrate it to President Rutherford B. Hayes. The reporter William Croffut dubbed him “The Wizard of Menlo Park,” and the nickname spread.⁠[3][1][3][2]

Many people had already attempted electric lighting, but none of it was suitable for home use. In September 1878, at the invitation of University of PennsylvaniaUniversity of PennsylvaniaThe University of Pennsylvania, commonly called Penn, is a private research university and Ivy League member in Philadelphia. It traces its origins to a 1740 charity-school project; Benjamin Franklin proposed his academy in 1749, classes began in 1751, and a 1791 merger established the institution under its present name. Penn has 12 schools, with undergraduate education concentrated in arts and sciences, engineering, nursing and Wharton. Enrollment totaled 29,384 in fall 2025, and the fiscal 2025 endowment was $24.81 billion. As of October 2026, J. Larry Jameson was president, with his term scheduled to end on June 30, 2027.Open the full entry physics professor George Barker, Edison visited the arc light system of William Wallace and Moses Farmer, and then announced that he would develop a complete electric lighting system to replace gas lighting in lower Manhattan. He modeled the system on gas lighting: power would be distributed through underground mains, wires would run through existing gas pipes, and customers would be billed by meter.⁠[1][7][8][8][8][8]

Later, a group of financiers joined Edison to form the Edison Electric Light Co., the predecessor of the later General Electric Company. To reduce the generating current and the cost of copper conductors, he determined that his lamps should have a high resistance of about 100 ohms and be connected in parallel circuits, so that each lamp could be turned on and off without affecting the others.⁠[5][7][7]

Edison first used platinum wire filaments, but platinum absorbed air when heated and became brittle; in March 1879 he began sealing the filament in a vacuum bulb. After improving his vacuum technology, he turned to carbon. On October 21–22, 1879, he and his assistants succeeded in experiments with a carbonized cotton thread filament in a vacuum, and the lamp glowed for thirteen and a half hours. On November 4, he filed the fundamental patent application for the carbon-filament incandescent lamp, which became U.S. Patent No. 223,898, granted on January 27, 1880.⁠[7][7][7][7][1][9][9]

In December 1879, Edison gave the first public demonstration of his incandescent lighting system, lighting up the Menlo Park laboratory complex with electric lamps; the New Year’s Eve demonstration drew hundreds of people by train, and the railroad added special cars for them. His achievement lay not only in inventing the incandescent lamp but in creating a complete electric lighting system that made the incandescent lamp practical, safe and economical.⁠[1][3][3][1]

He then experimented with many carbonizable materials and finally adopted bamboo as the commercial filament, which allowed bulbs to last more than 1,200 hours; in October 1880 he opened his first lamp factory at Menlo Park. While working on the lamp, he also noticed an electrical phenomenon that became known as the “Edison effect,” which became the basis of vacuum-tube electronics.⁠[7][9][2]

In February 1881, the Edison Electric Light Company established its headquarters in New York; that same year Edison left Menlo Park to set up factories and offices in New York and elsewhere, and spent the next five years manufacturing, improving and installing his electric power system around the world.⁠[3][2]

Edison received a total of 1,093 U.S. patents in his lifetime, covering telecommunications, electric power, sound recording, motion pictures, primary and storage batteries, mining and cement; he also had an estimated 500 to 600 patent applications that were unsuccessful or abandoned, and received 1,239 foreign patents in 34 countries. More than 300 companies were formed around the world to manufacture and market his inventions, many of them bearing the Edison name, including some 200 Edison illuminating companies.⁠[2][4][4][2]

Researchers consider that Edison broadened the concept of invention into an innovation process encompassing research, development and commercialization, and created the industrial research laboratory, establishing a model for modern industrial research. In 1973, he was inducted into the National Inventors Hall of Fame.⁠[2][2][5]