I'm pretty / 100% sure it was William Kemmler because he was the first person to be electrocuted or fried in the chair!! Am I right?
the eletric chair was invented by tomes edoson around1895
Alfred Southwick came up with idea to use electricity to execute people. Since he was a dentist, he made his device in the form of a chair. Harold Brown built the first electric chair for the Thomas Edison company. He used George Westinghouse's alternating current because Edison's direct current was losing favour.
Alfred P. Southwick developed the idea of using electric current as a method of execution when he saw an intoxicated man die after touching an exposed terminal on a live generator. As Southwick was a dentist accustomed to performing procedures on subjects in chairs, his electrical device appeared in the form of a chair. The first electric chair was made by Harold P. Brown. Brown was an employee of Thomas Edison, hired for the purpose of researching electrocution and for the development of the electric chair. Since Brown worked for Edison, and Edison promoted Brown's work, the development of the electric chair is often erroneously credited to Edison himself. Thomas Edison had been developing a direct current (DC) electrical system. The electric chair was designed to use alternative current (AC) in an effort to discredit the superior technology of George Westinghouse's alternating current (AC). Edison hoped to associate AC power with death and convince people that AC was unsafe for use in their homes. The first person to be executed via the electric chair was William Kemmler in New York's Auburn Prison on August 6, 1890. The first woman to be executed in the electric chair was Martha M. Place, executed at Sing Sing Prison on March 20, 1899.