Tesla moved to the US in 1884, and was charged with completely redesigning Edison's inefficient direct current generators, but left the company after less than two years over a disagreement about pay. This led to a lifelong feud between the two inventors and the so-called War of Currents, which was won by Tesla's system of alternating current in the following decade. In 1891, Tesla established his own laboratory in New York, and went on to not only pioneer modern day electrical engineering, but also contributed greatly to the fields of wireless technology, robotics, computer science and theoretical physics.

Despite his unparalleled scientific contributions, during his lifetime Tesla's genius was often overshadowed by his somewhat eccentric personality and penchant for seemingly outrageous (although sometimes entirely true) claims about future scientific and technological advancements. In particular, his later attempts to develop a directed-energy weapon, referred to in the press as a 'death ray', contributed greatly to his image as the prototypical mad scientist. After his death in 1943, Tesla's ashes were taken to Belgrade, and have resided in a gold-plated spherical urn at the Nikola Tesla Museum since 1957.