Opposition Party - United States - was created in 1854.
In the Federal Government of the United States, the opposition party is the Republican Party.
Workers Party of the United States was created in 1934.
Green Party of the United States was created in 1991.
Union Party - United States - was created in 1936.
Constitution Party - United States - was created in 1991.
Whig Party - United States - was created in 1833.
Justice Party - United States - was created in 2011.
Democratic Party - United States - was created in 1828.
World Socialist Party of the United States was created in 1916.
Socialist Equality Party - United States - was created in 1966.
Citizens Party of the United States was created on 2004-11-02.
Reform Party of the United States of America was created in 1995.