William McKinley was the 25th President of the United States. An immensely popular president who was assassinated by an anarchist early in his 2nd term. He was replaced by his Vice President, Theodore Roosevelt.
Perhaps McKinley would have garnered Roosevelt's place on Mount Rushmore had he not died of septic shock while attempting to recover from his shooting.
A man of compassion: Shortly after he was shot at the Pan American Exposition in Buffalo New York, when he saw assailant being beaten to the ground, he called out "Don't let them. hurt him."