Some members of the Anti-Slavery Society were dissatisfied with the radical leadership of William Lloyd Garrison, and in 1839 formed a rival organization, the American and Foreign Anti-Slavery Society. The following year they formed their own political party, the Liberty Party.

In the 1840 presidential election, the Liberty Party's candidate, James Birney won 7,000 votes. Four years later Birney increased this to 62,000. Gerrit Smith was their unsuccessful presidential candidate in 1848 and 1852.

In August 1848 members of the Liberty Party joined with anti-slavery members of the Whig Party to form the Free-Soil Party.