Leon Czolgosz was the assassin of President William McKinley. He was involved with various anarchist groups, and he was influenced by known anarchists such as Emma Goldman. On September 6, 1901, he shot and killed the president in Buffalo, New York. The assassination took place at the Pan-American Exposition, a large exposition/fair. Czolgosz was executed by the electric chair in New York's Sing Sing prison on October 29, 1901.