President William McKinley at the turn of the century, by Charles Parker

William McKinley Jr. (January 29, 1843 – September 14, 1901) was the 25th President of the United States, and the last veteran of the American Civil War to be elected to the office.

By the 1880s, McKinley was a national Republican leader; his signature issue was high tariffs on imports as a formula for prosperity, as typified by his McKinley Tariff of 1890. As the Republican candidate in the 1896 presidential election, he upheld the gold standard, and promoted pluralism among ethnic groups. His campaign, designed by Mark Hanna, introduced new advertising-style campaign techniques that revolutionized campaign practices and beat back the crusading of his arch-rival, William Jennings Bryan. The 1896 election is often considered a realigning election that marked the beginning of the Progressive Era.