Tesla emigrated from Serbia to the United States in 1884 with, by his own account, four cents in his pocket and a letter of introduction to Thomas Edison. The relationship with Edison didn't last, and for a stretch afterward Tesla worked digging ditches for two dollars a day just to get by, while still developing the ideas he'd eventually patent.
What he actually did
In October 1887, Tesla filed patents for a practical AC induction motor built around a rotating magnetic field, granted May 1, 1888. It eliminated the sparking brushes and commutators that limited earlier motor designs. George Westinghouse licensed the patents that same year, and the resulting AC system, covered in more detail in our War of the Currents guide, went on to win out over Edison's competing DC system entirely.
What makes him great
Most of the electrical industry at the time had already bet everything on DC. Tesla kept developing an idea most established players considered a dead end, and it turned out to be the one that actually scaled to power an entire country. He also, unlike a lot of inventors of his era, kept producing significant work for decades afterward, in radio, wireless power transmission, and electrical engineering more broadly, rather than resting on one success.
Sources
- IEEE Spectrum, "May 1888: Tesla Files His Patents for the Electric Motor."
- U.S. Energy Information Administration, "Nikola Tesla."
This is general educational information intended to build foundational understanding, not a comprehensive biography.
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