William McKinley was born in 1901.
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 . In 1876 , he was elected to Congress , where he became the Republican Party 's expert on the protective tariff , which he promised would bring prosperity . His 1890 McKinley Tariff was highly controversial ; which together with a Democratic redistricting aimed at gerrymandering him out of office , led to his defeat in the Democratic landslide of 1890 . The United States annexed the independent Republic of Hawaii in 1898 and it became a U.S. territory . Historians regard McKinley 's 1896 victory as a realigning election , in which the political stalemate of the post -- Civil War era gave way to the Republican-dominated Fourth Party System , which began with the Progressive Era .