Two-party system
Third parties, meaning a party other than one of the two dominant parties, are possible in two-party systems, but they are often unlikely to exert much influence by gaining control of legislatures or by winning elections. While there are occasional opinions in the media expressed about the possibility of third parties emerging in the United States, for example, political insiders such as the 1980 presidential candidate John Anderson think the chances of one appearing in the early twenty-first century is remote. A report in "The Guardian" suggested that American politics has been "stuck in a two-way fight between Republicans and Democrats" since the Civil War, and that third-party runs had little meaningful success.
History of the United States Republican Party
The Republican Party, also referred to as the GOP (abbreviation for Grand Old Party), is one of the world's oldest extant political parties. The party values reflect economic conservatism, classical conservatism (modern day American conservatism) and corporate liberty rights. It is the second oldest existing political party in the United States after its primary rival, the Democratic Party. The party emerged in 1854 to combat the Kansas–Nebraska Act, an act that dissolved the terms of the Missouri Compromise and allowed slave or free status to be decided in the territories by popular sovereignty. The early Republican Party had almost no presence in the Southern United States, but by 1858 it had enlisted former Whigs and former Free Soil Democrats to form majorities in nearly every Northern state.