On September 6, 1901, President William McKinley was shot twice by anarchist Leon Czolgosz while greeting visitors at the Pan-American Exposition in Buffalo, New York. The attack occurred during a public reception in the Temple of Music, where McKinley was shaking hands with attendees. At first, doctors believed the president would recover, and Vice President Theodore Roosevelt left Buffalo on vacation. Over the next several days, however, McKinley’s condition worsened due to infection. He died on September 14, and Roosevelt assumed the presidency, ushering in a new era of progressive reforms and increased federal activism.