After working in New York City to install the electric light system, Edison returned to New Jersey in 1887. He opened a new, larger laboratory in West Orange. More than 500 of Edison's patents came out of this lab.

Edison's most famous invention from his "Invention Factory" is the first movie viewer and movie camera, which he developed with William Kennedy Laurie Dickson.

Around this time, Edison returned to some of his earlier inventions to improve them. He "perfected" the phonograph in 1888, and in 1896, he began marketing a home phonograph. In the early 1900s, he worked on batteries, X-rays, and the first talking doll.

As the nation became involved in World War I, the U.S. military turned to Edison for help and advice. He was named head of the Naval Consulting Board, working primarily in submarine detection techniques.

Edison continued working at the Invention Factory through the 1920s. Although his health had begun to worsen, he was able to participate in a re-enactment of the invention of his incandescent light bulb in Dearborn, Michigan, in 1929. (Henry Ford, founder of Ford Motor Company, had reconstructed Edison's Menlo Park laboratory there.)

Edison died in 1931 at his New Jersey estate, Glenmont. To honor Edison, people across the nation dimmed their light bulbs for one minute on the day of his funeral.

Although Edison's laboratory closed after his death, the National Park Service preserved the West Orange laboratory as a national historic site. It is currently closed for renovations but is scheduled to reopen in 2005.