Political parties have shifted many times in 220 years of national politics. Even when parties have kept the same names for long periods, their issues, principles, supporters, and regional support all change over time.

This chart shows the evolution of political party systems in the U.S. from 1820 to 1860. Each "party system" is a roughly defined time period in which two major political parties, each with fairly consistent supporters and beliefs, dominated the political scene.

The colored lines represent organized parties that had a significant impact on national politics, electing members of Congress or receiving more than 1% of the vote for President. Where the lines merge and split, parties split or party affiliations changed dramatically in a short period of time. Presidential candidates are also listed for each party. The winner of each presidential election is designated with a bulls-eye.

Political parties in the United States, 1870-1900

Third party system (1868–1896)

The third party system emerged from divisions over slavery. The two major parties of the 1850s continued to dominate American politics after the Civil War. They are the same parties still in existence today, but their issues, beliefs, and supporters have changed many times.

After the Civil War, the major parties were tightly organized. In cities, party “bosses” organized voters, especially immigrants. Voters were extremely loyal to their parties, and voter turnout was high. Both parties were made up of coalitions of people with diverse interests.

At the national level, both parties were largely controlled by business interests in the 1880s and 1890s. During economic downturns, farmers in the South and West organized in opposition to both parties. These "Populists" failed to build a solid party organization, but they succeeded in putting farmers’ issues on the Democratic agenda.

Democratic

• After the Civil War, became essentially the only party in the South as African Americans were increasingly prevented from voting.
• In the North and West, support continued from farmers, workers, and Catholic immigrants as well as some businessmen who had opposed the Civil War.
• Continued to support a low tariff and economically conservative policies.
• Tended to oppose reforms such as Prohibition.
• After the Civil War, controlled at the national level by Northern businessmen.

Republican

• Adopted much of the antebellum Whig platform, supporting industry and urban growth, education, and division of western lands into homesteads for farmers.
• Strongly nationalist, supporting unity and expansion of national interests.
• More likely to support moral reform, including Prohibition.
• Supported by a coalition of northern businessmen, skilled craftsmen, professionals, commercial farmers, and African Americans.

People's (Populist)

• Supported mainly by farmers in the South and West. Tried but largely failed to build a coalition with industrial workers.
• Advocated government ownership of railroads and regulation of commerce.
• Best known for supporting expansion of the money supply, by printing "greenbacks" and ending the gold standard.
• Elected representatives to Congress, but failed to win a national election. Supported a "fusion" ticket with Democrats in 1896 and 1900.