Although political parties have no specific role under the U.S. Constitution, they are regulated by the constitutions of the individual states, which organize elections to both local and federal offices. Since the mid 1800s, the country has been limited to a two-party system with occasional inlets made by third parties. There have been many political parties other than the two dominant ones, but most third parties are generally considered to be of only minor and short-lived political significance.

  1. Democratic Party (c.1824 - Present)
  2. Republican Party (1854 - Present)
  3. Libertarian Party (1971 - Present)
  4. Constitution Party (formerly the U.S. Taxpayers Party) (1992 - Present)
  5. Green Party (1996 - Present)
  6. Alaskan Independence Party (1984 - Present)
  7. America First Party (2002 - Present)
  8. American Patriot Party (2003 - Present)
  9. American Party (1969 - Present)
  10. American Independent Party (1968 - Present)
  11. American Heritage Party (2000 - Present)
  12. American Nazi Party
  13. American Patriot Party (2003 - Present)
  14. American Reform Party (1997 - Present)
  15. Charter Party of Cincinnati, Ohio (1924 - Present)
  16. Christian Freedom Party (2004 - Present)
  17. Communist League (US) (2004 - Present)
  18. Communist Party USA (1919 - Present)
  19. Connecticut for Lieberman Party (2006 - Present)
  20. Conservative Party of New York (1962 - Present)
  21. Covenant Party (Northern Mariana Islands)
  22. Free People's Movement (2002 - Present)
  23. Independence Party of Minnesota (1992 - Present)
  24. Independence Party of New York (1991 - Present)
  25. Independent American Party (1998 - Present)
  26. Independent Citizens Movement (US Virgin Islands)
  27. Jefferson Republican Party
  28. Labor Party (1995 - Present)
  29. Liberal Party of Minnesota
  30. Liberal Party of New York (1944 - Present)
  31. Liberty Union Party (Vermont) (1970 - Present)
  32. Marijuana Party (2002 - Present)
  33. Marijuana Reform Party (New York) (1997 - Present)
  34. Moderate Party (2005 - Present)
  35. Mountain Party (West Virginia) (2000 - Present)
  36. New Party (1992 - 1998)
  37. New Progressive Party of Puerto Rico (1967 - Present)
  38. New Union Party (1974 - Present)
  39. New York State Right to Life Party (1970 - Present)
  40. Peace and Freedom Party (1967 - Present)
  41. Personal Choice Party (1997 - Present)
  42. Popular Democratic Party of Puerto Rico (1938 - Present)
  43. Populist Party of America (2002 - Present)
  44. Prohibition Party (1867 - Present)
  45. Puerto Rican Independence Party (1946 - Present)
  46. Reform Party of the United States of America (1995 - Present)
  47. Republican Moderate Party of Alaska (1986 - Present)
  48. Socialist Action (1983 - Present)
  49. Socialist Alternative (1986 - Present)
  50. Socialist Equality Party (1953 - Present)
  51. Socialist Labor Party (1876 - Present)
  52. Socialist Party USA (1972 - Present)
  53. Socialist Workers Party (1938 - Present)
  54. Southern Party (1999 - Present)
  55. Southern Independence Party
  56. United Party (Idaho) (2005 - Present)
  57. United Citizens Party (1969 - Present)
  58. Vermont Progressive Party (1999 - Present)
  59. Voter Rights Party
  60. Workers World Party (1959 - Present)
  61. Working Families Party (1998 - Present)
  62. Workers Party, USA
  63. World Socialist Party of the United States (1916 - Present)
  64. Federalist Party (c.1789 - 1816)
  65. Democratic-Republican Party (1792 - c.1824)
  66. Main article: Second Party System
  67. National Republican Party (1828 - 1837)
  68. Anti-Masonic Party (1828 - 1841)
  69. Nullifier Party (1830 - 1839)
  70. Whig Party (1832-1856)
  71. Liberty Party (1840 - 1848)
  72. Free Soil Party (1848 - 1855)
  73. American Party (“Know-Nothings”) (c. 1854 - 1858)
  74. Opposition Party (1854-1858)
  75. Constitutional Union Party (1860)
  76. National Union Party, (1864 - 1868)
  77. Liberal Republican Party (1872)
  78. Greenback Party (1874 - 1884)
  79. Anti-Monopoly Party (1884)
  80. Populist Party (1892 - 1908)
  81. National Democratic Party/Gold Democrats (1896 - 1900)
  82. Social Democratic Party (1900 - 1901)
  83. Home Rule Party of Hawaii (1900 - 1912)
  84. Socialist Party of America (1901 - 1973)
  85. Progressive Party 1912 (“Bull Moose Party”) (1912 - 1914)
  86. Non-Partisan League (1915 - 1956)
  87. Farmer-Labor Party (1918 - 1944)
  88. Progressive Party 1924 (1924)
  89. Communist League of America (1928 - 1934)
  90. American Workers Party (1933 - 1934)
  91. Workers Party of the United States (1934 - 1938)
  92. Union Party (1936)
  93. American Labor Party (1936 - 1956)
  94. America First Party (1944) (1944 - 1996)
  95. States' Rights Democratic Party (“Dixiecrats”) (1948)
  96. Progressive Party 1948 (1948 - 1955)
  97. Vegetarian Party (1948–1964)
  98. Constitution Party (United States 50s) (1952-1968 ?)
  99. Puerto Rican Socialist Party (1959 - 1993)
  100. Mississippi Freedom Democratic Party (1964)
  101. Communist Workers Party (1969 - 1985)
  102. People's Party (1971 - 1976)
  103. U.S. Labor Party (1975-1979)
  104. Citizens Party (1979–1984)
  105. New Alliance Party (1979 - 1992)
  106. Christian Falangist Party of America (1985-2006)
  107. Populist Party 1990's (1984 - 1994)
  108. Looking Back Party (1984 - 1996)
  109. Grassroots Party (1986-2004)
  110. Independent Party of Utah (1988-1996)
  111. Greens/Green Party USA (1991-2005)
  112. Natural Law Party (1992 - 2004)