Today is the birthday of William McKinley. He was the twenty-fifth president of the United States and sadly was the third president assassinated within a thirty-six year period. McKinley's time in office is marked by a few significant events from the annexation of Hawaii to the Spanish American War. His second term ended abruptly when anarchist Leon Czolgosz shot him in Buffalo, New York. Learn more about William McKinley and his time in office by reading his biography.