1896 was a game changer for politics in the United States. The season can be pinpointed as the dividing line between the Third Party and Fourth Party systems in American politics. The financial crisis of 1893 was also weighing heavily on the national conscience. It also saw the beginning of the standing practice of politicians soliciting donations directly from financiers and industrialists, instead of financing through wage cuts donations from incumbents.
The Third Party System, which began around 1854 is closely associated with the U.S. Civil War. Mainline issues include Reconstruction, race, and monetary policy. It is characterized by strong party loyalty, rigid hierarchal organization, and the spoils system. We see the rise of 'Party Bosses' in large municipalities during the Third Party, like Boss Tweed running the Tammany Hall Machine.
The Election of 1896 was a showdown of the Republican Party versus the Democratic Party & Coalition consisting of the Populist Party and the Silver Republican Party. Three other parties ran candidates, none receiving Electoral College votes, and therefor I will mention them no more.
The Republicans, easily put up McKinley and Reed on the first round of their convention. The foundation of their campaign was to be pro-business and continue the gold standard. It had broad support with industrialists, businessmen, skilled labor, and wealthy landed.
Earning the Democratic Coalition nomination William J. Bryan and a strange double ticket for the Vice Presidential double ticket of Bryan-Arthur Sewal (Democrat) and Bryan-Thomas Watson (Populist).
McKinley, over the course of the campaign would raise $3.5 million dollars compared to the $500,000 that Bryan was able to raise. He was able to promote and distribute literature with a positive outlook of a McKinley presidency, while demonizing Bryan as a religious fanatic who would devalue the currency by switching to the Silver Standard.
The rise of the Fourth Party System saw the age of the trusts come to pass. While it was an era thoroughly bought politicians at every level of government, new laws weakened the party boss system, created the primaries, and the direct election of Senators. The North East and west became Republican entrenchments, and the Solid South rose for the Democrats. The office of the President was held by Republicans with very pro-business leanings with the exception of the schism of Teddy Roosevelt (who directly helped Wilson get elected). The Fourth Party System would last until the dawn of the Great Depression.
Sources:
Cherny, Robert. American Politics in the Gilded Age 1868-1900 (1997)
Dinkin, Robert J. Campaigning in America: A History of Election Practices. (1989)
Horner, Williams. Ohio's Kingmaker: Mark Hana Man & Myth (2010)
Jensen, Richard. Grass Roots Politics: Parties, Issues, and Voters, 1854–1983 (1983)
Ware, Alan. The American Direct Primary: Party Institutionalization and Transformation in the North (2002)
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