Nikola Tesla was born at midnight on July 9, 1856, in the village of Smiljan, in the province of Lika, Croatia—then part of the Austro-Hungarian Empire. Tesla was the genius who ushered in the age of electrical power.

Tesla had a vivid imagination and an intuitive way of developing scientific hypotheses. After seeing a demonstration of the "Gramme dynamo" (a machine that when operated in one direction is a generator, and when reversed is an electric motor), Tesla visualized a rotating magnetic field and developed plans for an induction motor applying the concept. This electric motor was the first step toward the successful application of alternating-current. Telsa used his imagination to prove and apply his hypotheses. Here is how he explained his creative process:

“Before I put a sketch on paper, the whole idea is worked out mentally. In my mind I change the construction, make improvements, and even operate the device. Without ever having drawn a sketch I can give the measurements of all parts to workmen, and when completed all these parts will fit, just as certainly as though I had made the actual drawings. It is immaterial to me whether I run my machine in my mind or test it in my shop. The inventions I have conceived in this way have always worked. In thirty years there has not been a single exception. My first electric motor, the vacuum wireless light, my turbine engine and many other devices have all been developed in exactly this way.”

Tesla completed his elementary education in Croatia. He continued his schooling in the Polytechnic School in Graz and finished at University of Prague. He worked as an electrical engineer in Germany, Hungary and France before emigrating to the United States in 1884.

Arriving in New York City with four cents in his pocket, Tesla found employment with Thomas Edison in New Jersey. Differences in style between the two men soon led to their separation. In 1885, George Westinghouse, founder of the Westinghouse Electric Company, bought patent rights to Tesla's system of alternating-current. The advantages of alternating-current over Edison's system of direct-current became apparent when Westinghouse successfully used Tesla's system to light the World Columbian Exposition at Chicago in 1893.

Tesla established a laboratory in New York City in 1887. His experiments ranged from an exploration of electrical resonance to studies of various lighting systems. To counter fears of alternating-current, Tesla gave exhibitions in his laboratory in which he lighted lamps without wires by allowing electricity to flow through his body.

When Tesla became a United States citizen in 1891, he was at the peak of his creative powers. He developed in rapid succession the induction motor, new types of generators and transformers, a system of alternating-current power transmission, fluorescent lights, and a new type of steam turbine. He also became intrigued with wireless transmission of power.

In 1900, Tesla began construction on Long Island of a wireless broadcasting tower. The project was funded with $150,000 capital from financier J. Pierpont Morgan. The project was abandoned when Morgan withdrew his financial support. Tesla's work shifted to turbines and other projects, but his ideas remained on the drawing board due to a lack of funds. Tesla's notebooks are still examined by engineers in search of unexploited ideas.

Tesla allowed himself few close friends, although one was humorist and author, Mark Twain. However, when he died in New York City on January 7, 1943, hundreds of admirers attended his funeral services, mourning the loss of a great genius. At the time of his death Tesla held over 700 patents.