Final answer:
The growing opposition to slavery in the United States from 1776 to 1850 was driven by the formation of political parties opposing its expansion, abolitionist activism raising public consciousness, and differing perspectives on liberty and the legacy of the American Revolution.
Step-by-step explanation:
The opposition to slavery in the U.S. from 1776 to 1850 was fueled by several key factors. Political movements, concerned with the morality and expansion of slavery, led to the formation of parties like the Liberty Party, the Free-Soil Party, and the Republican Party. These groups challenged slavery's expansion to the West, arguing it conflicted with American notions of property rights and liberty. Abolitionists, such as William Lloyd Garrison, characterized slavery as a national sin and called for its immediate end, heightening public awareness and bringing the debate to the forefront of national consciousness.
The contrasting interpretations of liberty and the legacy of the American Revolution between northerners and southerners further deepened the division. Inspirations from the Enlightenment and the French Revolution spurred intellectual debates among a minority, questioning the justification of slavery. As tensions escalated, the 1850s witnessed confrontations, like John Brown's raid on Harper's Ferry, signaling a drift toward inevitable conflict.