Two-party system
A two-party system is a party system where two major political parties dominate the government. One of the two parties typically holds a majority in the legislature and is usually referred to as the "majority" or "governing party" while the other is the "minority" or "opposition party". Around the world, the term has different senses. For example, in the United States, Jamaica, and Malta, the sense of "two-party system" describes an arrangement in which all or nearly all elected officials belong to one of the only two major parties, and third parties rarely win any seats in the legislature. In such arrangements, two-party systems are thought to result from various factors like winner-takes-all election rules. In such systems, while chances for third-party candidates winning election to major national office are remote, it is possible for groups within the larger parties, or in opposition to one or both of them, to exert influence on the two major parties. In contrast, in the United Kingdom and Australia and in other parliamentary systems and elsewhere, the term "two-party system" is sometimes used to indicate an arrangement in which two major parties dominate elections but in which there are viable third parties which do win seats in the legislature, and in which the two major parties exert proportionately greater influence than their percentage of votes would suggest.
Party switching in the United States
The first two major parties in the United States were the Federalist Party and the Democratic-Republican Party. The Federalists experienced success in the 1790s but lost power in the 1800 elections and collapsed after the War of 1812. Many former Federalists, including John Quincy Adams, became members of the Democratic-Republican Party. After the 1824 presidential election, the Democratic-Republicans fractured between supporters of Adams and supporters of Andrew Jackson. Jackson's followers formed the Democratic Party, while those who supported Adams formed the National Republican Party. Two short-lived but significant third parties, the Anti-Masonic Party and the Nullifier Party, also arose during this period. In the 1830s, opponents of Jackson coalesced into the Whig Party.