John Quincy Adams was elected to the House of Representatives after leaving the Presidency - the only President to ever do this. There "Old Man Eloquent" continued to fight for what he believed was right. One of these fights was against the "gag" rule. He actually tried to motion against it even as it was being passed in 1836.
The National Archives has an online exhibit that explains the history of this controversary:
The Constitution guarantees citizens the right "to petition the government for a redress of grievances." Nineteenth-century Americans exercised this right vigorously. Each session, Congress received petitions "respectfully," but "earnestly praying" for action. In 1834 the American Anti-Slavery Society began an antislavery petition drive. Over the next few years the number of petitions sent to Congress increased sharply. In 1837—38, for example, abolitionists sent more than 130,000 petitions to Congress asking for the abolition of slavery in Washington, DC. As antislavery opponents became more insistent, Southern members of Congress were increasingly adamant in their defense of slavery.
In May of 1836 the House passed a resolution that automatically "tabled," or postponed action on all petitions relating to slavery without hearing them. Stricter versions of this gag rule passed in succeeding Congresses. At first, only a small group of congressmen, led by Representative John Quincy Adams of Massachusetts, opposed the rule. Adams used a variety of parliamentary tactics to try to read slavery petitions on the floor of the House, but each time he fell victim to the rule. Gradually, as antislavery sentiment in the North grew, more Northern congressmen supported Adams’s argument that, whatever one’s view on slavery, stifling the right to petition was wrong. In 1844 the House rescinded the gag rule on a motion made by John Quincy Adams.
The online exhibit includes the handwritten gag rule, J.Q. Adams handwritten objection to it as well as a slavery petition.
You can see Adams' efforts against this rule in these House transcripts that Dr. Margaret Zulick has posted online:
Question of Non-Reception
Petition Purporting to Come from Slaves