Adams's increasing independence from any particular political party allowed him to champion the rights of the antislavery (abolitionist) movement. Adams said he felt "bonded" by the Constitution to work for universal emancipation (freedom for all).

In 1836, Southern members of Congress got the House to pass a "gag rule" that forbade discussion of slavery in the House of Representatives. Adams fought tirelessly against the gag rule, and in 1844 he finally succeeded in getting it abolished, by a vote of 108 to 80. What event most highlighted Adams's fight against slavery?