William McKinley is best known for being president when the United States acquired Puerto Rico, Guam, and the Philippines.

• William McKinley Jr. was the 25th president of the United States, serving from March 4, 1897, until his assassination six months into his second term.
• Born: January 29, 1843, Niles, OH
• Assassinated: September 14, 1901, Buffalo, NY
• Presidential term: March 4, 1897 – September 14, 1901
• Party: Republican Party
• Spouse: Ida Saxton McKinley (m. 1871–1901)
• Vice presidents: Garret Hobart (1897–1899), Theodore Roosevelt (1901)
• First president to ride in an automobile. He rode with Freelan Oscar Stanley of the Stanley Motor Carriage Company in his steam car in 1899. He also rode in an electric ambulance that carried him to the hospital where he was treated after being shot.
• First president to serve as permanent chairman of the Republican National Convention.
• First president inaugurated in the 20th century.
• First president to have his inauguration filmed.