Are there only two parties in American politics?

There are two major parties in the United States - the Democratic Party and the Republican Party.

Founded in 1792 by Thomas Jefferson and James Madison, the Democratic Party has positioned itself as the liberal party on domestic issues since 1912.
In 2004, it was the largest political party, with 72 million registered voters. Although his party lost the 2004 elections, Barack Obama later went on to become president in 2009 and continued to be the president until January 2017.

Obama was the 15th Democrat to hold the office, and from the 2006 midterm elections until the 2014 midterm elections, the Democratic Party was also the majority party in the United States Senate.

The second major party, the Republican Party has been nicknamed the "Grand Old Party" or GOP, although it is younger than the Democratic Party.

Founded in 1854 by anti-slavery activists, the Republican Party rose to prominence with the election of Abraham Lincoln in 1860. The Republican Party has been the more market-oriented of the two American political parties, often favouring policies that help business interests.

With roughly 55 million registered members (as of 2018), the Republican Party is the second largest party in the United States.

Since the 2010 midterm elections, the Republicans held a majority in the House of Representatives, until the 2018 midterms where they lost to the Democrats. Since 2014, Republicans have controlled the Senate.

America also has a host of minor parties. Based on support for their Presidential candidates in the 2016 elections, the largest are the Libertarian, Green, and Constitution parties.

No candidate from minor parties have ever won a Presidential Election in the United States.