 History can turn on a dime. In America's case, that's what happened on September 6, 1901, when President William McKinley stepped in front of a receiving line at the Pan American Exposition in Buffalo, New York. An anarchist named Leon Salgaz waited his turn in the long line. When he stepped forward to shake hands with President McKinley, he suddenly pulled a .32 caliber revolver from his jacket pocket and fired twice at point-blank range.