What did the term Conscience Whigs mean for Samuel Gridley Howe and other antislavery Whigs?

For Samuel Gridley Howe and other antislavery activists, the term Conscience Whigs served as a vital political distinction used to separate themselves from the so-called Cotton Whigs.1

While the Whig Party was often divided by sectional interests, the Conscience Whigs were defined by their firm opposition to the expansion of slavery. In contrast, Cotton Whigs—such as U.S. Senator Daniel Webster—were characterized by their sympathy toward Southern slavery and their willingness to prioritize party unity over abolitionist principles.321

By adopting the label of Conscience Whigs, Howe and his allies signaled their refusal to align with the proslavery factions of their party. This ideological rift eventually led many of these individuals to abandon the Whig Party entirely, particularly following the Compromise of 1850, which fatally estranged them from the organization. Ultimately, these antislavery Whigs became instrumental in the formation of the Free-Soil Party and, later, the Republican Party.132