Leon Czolgosz, a 28-year-old anarchist follower of Emma Goldman who believed government (and its leaders) prevented "complete individual liberty," also traveled to Buffalo for the Exhibition. But Czolgosz (pronounced cholgosh) had a different reason for being there. He planned to kill the popular President.

McKinley had given a speech at the Expo on September 5. The next day, shortly after 4 p.m., on September 6, he was meeting people at the Temple of Music. Ostensibly in line to shake McKinley’s hand, Czolgosz pulled out a .32 caliber short-barreled Johnson revolver and shot the President twice. One shot caused only a non-penetrating flesh wound. The other ripped through the President’s stomach.

A quick-thinking waiter, James Benjamin ("Big Jim") Parker who worked at one of the Expo’s restaurants, jumped Czolgosz. His heroic actions prevented a third shot.

Freely confessing what he did, the assassin told the police what happened. The local newspaper quoted the District Attorney:

This man has admitted shooting the President. He says he intended to kill; that he has been planning to do it for the last three days since he came here. He went into the Temple of Music with murder in his heart, intending to shoot to kill. He fixed up his hand by tying a handkerchief around it and waited his turn to get near the President, just as the newspapers have described. When he got directly in front of the President he fired. He says he had no confederates, that he was entirely alone in the planning and execution of his diabolical act.