On September 6, President McKinley visited Niagara Falls and Lewiston, New York. He rode the gorge railway and had a splendid time. He returned to the Exposition for an afternoon reception at the Temple of Music.
It was a hot, late-summer day, and the building was very warm. Many people had handkerchiefs to wipe the sweat from their brows. There was a long line of people waiting to shake McKinley's hand. No one paid any attention to the fact that Leon Czolgosz had a handkerchief wrapped around his right hand. The President extended his left hand to the young man – then Czolgosz shot him twice with a gun hidden in the handkerchief.
The President was hit in the upper abdominal area. Immediately after the shooting, the men standing nearby wrestled Czolgosz to the ground. He was taken into custody while McKinley awaited the electric-powered ambulance. Upon seeing Czolgosz being beaten, McKinley told the men to “go easy on him.”
McKinley was taken to the Exposition Hospital, where surgery was performed. He was later moved to the home of John Milburn, President of the Pan-American Exposition. Theodore Roosevelt, who was in Vermont at the time of the shooting, was hastily notified.
As McKinley's condition continued to improve, Roosevelt felt it was safe to leave Buffalo. On Tuesday night he took an all-night train to the Adirondack Mountains, where his family was already on vacation. He left detailed instructions with Ansley Wilcox should his presence in Buffalo again be necessary.