He invented the electrical system that powers the modern world, was cheated by Edison, outmaneuvered by rivals, and died penniless in a hotel room — then spent decades being forgotten.
Nikola Tesla emigrated from Serbia to the United States in 1884 with four cents in his pocket, a letter of introduction, and a head full of ideas. He went straight to Thomas Edison's lab in New York, where he worked grueling hours improving Edison's direct-current systems. Edison allegedly promised him $50,000 to solve a set of engineering problems. When Tesla succeeded, Edison told him he had been joking.
Tesla quit Edison's company and eventually partnered with George Westinghouse to develop alternating current — a fundamentally different system for transmitting electricity that could travel long distances without losing power. Edison, who had bet his business on direct current, fought back with a vicious propaganda campaign, electrocuting animals in public demonstrations to 'prove' AC was dangerous. The 'War of Currents' ended with AC winning. The world runs on Tesla's system.
Tesla's mind operated at a level his contemporaries couldn't fully follow. He invented the AC induction motor, the polyphase electrical supply system, the Tesla coil, early radio technology, the first radio-controlled vehicle, and conducted some of the earliest X-ray research. He envisioned wireless power transmission decades before it was possible — and poured his fortune into a tower on Long Island intended to transmit electrical power through the Earth to anyone on the planet.
J.P. Morgan funded the Wardenclyffe Tower project, then pulled his support when he realized there was no way to meter and sell wirelessly transmitted power. Without funding, the tower was never completed. Tesla spiraled into financial ruin. He spent his later years in New York City hotels, moving when he couldn't pay his bills, increasingly eccentric, feeding the pigeons in Bryant Park.
Tesla died alone in Room 3327 of the New Yorker Hotel on January 7, 1943, at age 86. He owed back rent. He had given away or lost the rights to most of his patents. Within hours of his death, government agents arrived and confiscated his papers — fearing they contained secrets related to his theoretical weapons work. Much of his archive remained classified for years.
The rehabilitation of Tesla's reputation took most of a century. Edison died famous and celebrated; Tesla died broke and obscure. In 1960, the international scientific community named the SI unit of magnetic flux density the 'tesla' in his honor. Today he is recognized as one of the most important inventors in human history — a man who was simply too far ahead of his time, and the wrong kind of eccentric, to profit from his own genius.