Leon Czolgosz shoots President McKinley with a concealed revolver, at the Pan-American Exposition.

Leon F. Czolgosz (1873 - October 31, 1901) was the assassin of U.S. President William McKinley.

One of seven children of Russian-Polish immigrants, Czolgosz lived in conditions of brutal poverty for most of his life. He left his family farm in Cleveland, Ohio at the age of ten to work at American Steel and Wire Company with two of his brothers. At the height of his employment he was making $4 a day, but after the workers of his factory went on strike (with no union to protect them), they were fired. In 1898, after witnessing a series of similar strikes (many ending in police confrontation), Leon suffered a mental breakdown and had to return home, where he was constantly at odds with his family's Roman Catholic beliefs, and with his stepmother (his mother had died during childbirth when he was twelve). He became a recluse, and spent much of his time alone, reading socialist and anarchist newspapers. He frequented the speeches of Emma Goldman.

In 1901, he moved to Buffalo, New York and rented a room near the site of the Pan-American Exposition. On September 6, 1901, Czolgosz went to the exposition with a pistol in his hand, concealed in a bandage. McKinley had been standing in a receiving line greeting the public for several minutes when Czolgosz shot McKinley twice at point blank range. McKinley would die from his wounds on September 14.

After a short trial, Czolgosz was found guilty and executed by electrocution on October 31, 1901. His last words were "I killed the President because he was the enemy of the good people — the good working people. I am not sorry for my crime."

The gun used by Czolgosz was an Iver-Johnson "Safety Automatic" revolver in .32 S&W caliber, serial number 463344.\n