The Liberty Party was an abolitionist political party in the United States before the American Civil War. The party experienced its greatest activity during the 1840s, while remnants persisted as late as 1860. It supported James G. Birney in the presidential elections of 1840 and 1844. Others who attained prominence as leaders of the Liberty Party included Gerrit Smith, Salmon P. Chase, Henry Highland Garnet, Henry Bibb, and William Goodell. They attempted to work within the federal system created by the United States Constitution to diminish the political influence of the Slave Power and advance the cause of universal emancipation and an integrated, egalitarian society.

In the late 1830s, the antislavery movement in the United States was divided between Garrisonian abolitionists, who advocated nonresistance and anti-clericalism and opposed any involvement in electoral politics, and Anti-Garrisonians, who increasingly argued for the necessity of direct political action and the formation of an anti-slavery third party. At a meeting of the American Anti-Slavery Society in May 1840, the Anti-Garrisonians broke away from the Old Organization to form the American and Foreign Anti-Slavery Society. The New Organization included many political abolitionists who gathered in upstate New York to organize the Liberty Party ahead of the 1840 elections. They rejected the Garrisonian singular emphasis on moral suasion and asserted that abolitionists should oppose slavery by all available means, including by coordinating at the ballot box.

The party attracted support from former Whigs and Jacksonian Democrats alienated by their parties' proslavery national leaderships, as well as the early involvement of women and African Americans. Internal disagreements over whether and how the party should cooperate with abolitionists who remained within the two major parties and to what extent Liberty candidates should address issues beyond slavery intensified after 1844. In 1847 party leaders favoring a coalition with antislavery Conscience Whigs and Barnburner Democrats succeeded in nominating John P. Hale for president over Gerrit Smith, the candidate of the radical Liberty League. Hale was an Independent Democrat who had opposed the gag rule in Congress and voted against the annexation of Texas but stopped short of endorsing immediate emancipation. Following the 1848 convention of antislavery politicians at Buffalo, New York, Hale withdrew from the race in favor of Martin Van Buren, and most of the Liberty Party folded into the larger Free Soil Party. Smith and the Liberty League continued to maintain a separate organization and supported an independent ticket in each ensuing election until 1860. Many former Liberty leaders subsequently became founders of the Republican Party, including Salmon Chase.

History Creation, 1839–41

Efforts by abolitionists to organize politically began in the late 1830s. The earliest attempts were not made with a new party in mind, as abolitionists hoped to influence the two existing parties. Antislavery voters in New England demanded candidates announce their position on slavery and awarded or withheld their support accordingly. The success of the "questioning system" proved fleeting, however, as abolitionists discovered candidates frequently would issue antislavery pledges during a campaign, only to abandon their commitments once elected. As party organizations resumed their place as the drivers of national politics after 1828, the need for a dedicated antislavery party to effectively oppose the bipartisan proslavery consensus gradually gained recognition. After 1837, the Democratic Party leadership sought actively to expel antislavery Jacksonians such as Thomas Morris and John P. Hale whose principled opposition to slavery was seen as a threat to party unity. While the Whig Party sometimes sought to ingratiate itself with abolitionists, the influence of southern nullifiers and proslavery northern Cotton Whigs prevented the party from taking a strong antislavery stance. Committed to the union of the states, both parties sought to suppress issues such as slavery which threatened to split the country along sectional lines.

The overwhelming hostility of the established parties encouraged a growing opinion in abolitionist circles favoring creation of an independent antislavery party. The first movement toward this object took place at Warsaw, New York, at an abolitionist meeting led by Myron Holley, formerly one of the commissioners of the Erie Canal. The assembly nominated James G. Birney for president and called for a national convention of political abolitionists to meet at Albany, New York, to organize the new party.. Holley's prior efforts to persuade the AASS to support a presidential ticket had ended in failure; he along with others, including Henry B. Stanton and Elizur Wright, were early leaders in the movement to organize a new, antislavery party. Holley, however, would die before he could play a larger role in the leadership of the Liberty Party The Albany convention was attended by 121 delegates from six states who nominated Birney for president and Thomas Earle for vice president on April 1, 1840. The initial response to the Albany convention was lukewarm; while the Garrisonians continued to oppose any involvement in electoral politics, others felt the nominations were premature and that the political abolitionists needed more time to persuade their colleagues of the necessity of independent political action for the new party to be successful. Nevertheless, electoral tickets pledged to Birney and Earle were organized in every free state. Concerns that the party was still too young to attract the support of most abolitionists proved warranted. Birney polled fewer than 7,000 votes in the 13 states where there were electors pledged to him; in four of these (Connecticut, Indiana, New Jersey, and Rhode Island), he received fewer than 100 votes. He received no votes from the slave states, where the party had not been organized. The Whig ticket of William Henry Harrison and John Tyler was elected with 234 electoral votes to 60 for the incumbent Democrat Martin Van Buren; Harrison's share of the vote in the free states (52.42%) dwarfed Birney's less than one percent showing.

The party initially went by a number of different names, including the Human Rights Party, the Abolition Party, and the Freemen's Party. The 1841 Liberty National Convention selected the "Liberty Party" as the movement's official name.

Rise, 1841–43

The Liberty Party experienced rapid growth in the years following the 1840 United States elections, particularly in New England and areas of Yankee settlement. Events in Washington helped drive support for antislavery politics. In April 1841, Harrison died and was succeeded by Vice President Tyler, who became the 10th president of the United States. A Virginian and a slaveholder, Tyler was one of the southern conservatives who joined the Whig Party after 1834 to oppose the expansion of executive power under Andrew Jackson. Tyler broke with Whig congressional leaders over the proposal to recharter the Bank of the United States, leading to his exit from the Whig Party before the end of 1841; significantly for abolitionists, he was an early and ardent advocate of the annexation of Texas. Tyler believed American acquisition of Texas was necessary to secure the future of slavery in the United States; he, along with Secretary of State John C. Calhoun, feared that if Texas became aligned with the British Empire, it would become a haven for freedom seekers and weaken slavery in the Lower South. Abolitionists drew similar conclusions and opposed Texas annexation as a measure likely to increase the political might of the Slave Power. The Tyler-Texas Treaty drew opposition from moderate antislavery congressmen as well, including Hale and Benjamin Tappan. As northern opposition to annexation mounted, the indecision of the Whigs and Democrats increased the attractiveness of the Liberty Party to antislavery voters as the only principled anti-annexation party.

Between 1841 and 1843, abolitionist opinion shifted perceptibly in favor of independent political action, and the Liberty Party was the recipient of this outpouring of support. While William Lloyd Garrison remained a prominent and influential figure, the failure of moral suasion discredited the approach of the AASS, and by 1844, "the Liberty Party was the major vehicle for serious abolitionist sentiment in every state." This support translated to scattered successes in local and state legislative races in areas where abolitionists were an organized and active majority of voters. Elsewhere, Liberty voters could play kingmaker in areas where neither opposing party controlled a majority of the electorate. In the highly competitive and closely divided environment of the Second Party System, even a modest showing for the Liberty candidates could have deep and lasting effects. Six Liberty members were elected to the Massachusetts General Court in 1842, where they held the balance of power in the divided legislature. That year, Samuel Edmund Sewall polled 5.4 percent as the Liberty candidate for governor, enough to hold both leading candidates below a majority and send the election to the Massachusetts Senate. The strategy of the Liberty members to leverage their votes to produce a deadlock narrowly failed when one Whig member voted with the Democrats to ensure the abolitionists' defeat, and John Greenleaf Whittier wrote that Sewall "came within a hair's breadth of being governor."

The 1842 campaign in Massachusetts raised significant questions in the internal debate over party strategy. Most Liberty members conceived of the party as a moral crusade to purify American politics from the corrupting influence of the Slave Power. They had renounced their past party allegiances in the belief that the established parties were institutionally committed to slavery and therefore incapable of being converted to abolitionist principles. Many disavowed any cooperation with the established parties, even when local candidates had proven antislavery records. While Independent Democrats like Hale and Conscience Whigs like John Quincy Adams and Joshua Reed Giddings might share some abolitionist priorities, they would still campaign for their parties' proslavery national candidates and did not support immediate, universal emancipation. Editors like Joshua Leavitt of The Emancipator and James Caleb Jackson of the Utica Liberty Press argued that helping to elect such "major party" opponents of slavery ultimately strengthened the Slave Power by extending the life of the established proslavery parties; they called for the Liberty Party to remain an independent organization and work to defeat the proslavery parties outright. Another faction, based in Ohio, sought a coalition with antislavery Whigs and Democrats. Led by Salmon P. Chase and Gamaliel Bailey, they aimed to broaden the party's appeal beyond the abolitionist movement by emphasizing opposition to slavery's extension and the negative effects of slavery for white northerners.