Nikola Tesla

Nikola Tesla (July 10, 1856 – January 7, 1943) was a Serbian American (back in the time of Austro-Hungarian Empire, modern-day Croatia), famous as an inventor and a mechanical and electrical engineer.

Real world
Tesla is best known for many revolutionary contributions in the field of electricity and magnetism in the late 19th and early 20th centuries. Tesla's patents and theoretical work formed the basis of modern alternating current (AC) electric power systems. At the time of his death, Tesla had been continuing his work on the teleforce weapon, or death ray, that he had unsuccessfully marketed to the US War Department. It appears that his proposed death ray was related to his research into ball lightning and plasma, and was imagined as a particle beam weapon.

Immediately after Tesla's death became known, the government's alien property custodian and Yugoslavian Consulate office took possession of his papers and property, despite his US citizenship. His safe at the hotel was also opened. The US government did not find a prototype of the device in the safe. After the FBI was contacted by the War Department, his papers were declared to be top secret.

Fallout world
In the 21st century, a Tesla armor was constructed for United States military use based on his plans. Though his plans looked completely insane, they worked like a charm. The result was a shining metal armor providing superior protection against energy attacks thanks to the three Tesla attraction coil rods which disperse a large percentage of directed energy attacks. Against conventional weaponry it acts as regular metal armor. Later, after the Great War, the Enclave constructed a Tesla power armor.

A book titled Nikola Tesla and You was published before the War, instructing readers how to operate various energy weapons (some of which, like the Tesla cannon, could have been based on Tesla's designs).