5854144 President William McKinley, c.1900 (b/w photo) by American Photographer, (19th century); Private Collection; (add.info.: William McKinley (1843-1901) 25th President of the United States, from 1897 until his assassination in September 1901, six months into his second term. Last president to have served in the American Civil War and the only one to have started the war as an enlisted soldier, beginning as a private in the Union Army).