William McKinley was an American.
The Fourth Party System is the term used in political science and history for the period in American political history from about 1896 to 1932 that was dominated by the Republican Party , excepting the 1912 split in which Democrats held the White House for eight years . The Tariff Act of 1890 , commonly called the McKinley Tariff , was an act of the United States Congress framed by Representative William McKinley that became law on October 1 , 1890 . The United States Congress is the bicameral legislature of the federal government of the United States consisting of two chambers : the Senate and the House of Representatives . William McKinley Jr. ( January 29 , 1843 -- September 14 , 1901 ) was an American politician and lawyer who served as the 25th President of the United States from March 4 , 1897 until his assassination in September 1901 , six months into his second term . McKinley was the 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 and ending as a brevet major .