In 1884, Tesla went to the United States and worked for a short time for Thomas Edison, but quit over a salary dispute and clashing personalities (Tesla simply envisioned his inventions, while Edison invented with hard-labor, trial and error). In the 1880's and 1890's Edison was working on Direct Currents and Tesla was working on Alternating Currents. Tesla's system prevailed. Tesla's Alternating Current (AC) System for a power project was licensed by George Westinghouse in 1893 for the World's Columbian Exposition, where Tesla actually conducted demonstrations of his AC system. In 1895, Tesla designed the first hydroelectric power plant at Niagara Falls, which was highly promoted worldwide. Tesla sold several patent rights to Westinghouse, including the alternating-current machinery. Westinghouse ran into problems when Westinghouse's backers would not work with Tesla. Tesla tore up his contract with Westinghouse, which ended up costing Tesla millions of dollars in royalties.
Tesla is also famous for inventing the rotating magnetic field, neon and fluorescent lights, the system of arc lighting, the Induction Motor, the system of Wireless Communication (which led to the Internet) and the famous "TESLA COIL" (1891), producing high-voltage, low current, high-frequency alternating current electricity. Tesla experimented with electromagnetic waves, which formed the basis of the development of radio. His systems made it possible to supply electricity over hundreds of miles, instead of short distances, which was the standard at the time.
Tesla was a showman and loved to demonstrate his inventions. There was even a promotional photo taken of Tesla in his Colorado Springs Laboratory showing millions of electrical volts flying around Tesla, as he calming sits and reads. The genius American author and humorist Mark Twain was a friend of Tesla and visited his laboratory in 1899 to see his inventions for himself. Reportedly, Twain's book "A Connecticut Yankee in King Arthur's Court", about a time traveler introducing modern technology to England, was influenced by Tesla. Tesla was known for his obsessive, eccentric personality and for being a total recluse. He refused to marry, reportedly claiming that his chastity was necessary for his scientific discoveries. Tesla refused the Nobel Prize in 1912, which was awarded to Tesla and Edison.
Due to the lack of funds supporting Tesla, most of his inventions are only written in a notebook. On Jan. 7, 1943, Tesla died. Allegedly Tesla was penniless and in debt when he died alone, in Room 3327, of the New Yorker Hotel in New York City at the age of 86.
Tesla held over 700 patents in his lifetime and changed the face of electricity.