After 1829 when Stuart went of to preach about the abolition of West Indian Slavery, weld had become engulfed in Anti-Slavery. Soon after 1830 Weld had started working with Arthur and Lewis Tappan and became one of the leaders in the Anti-Slavery movement. While on a quest to find a good site for seminaries, Weld advocated every chance he got. While supplying a bulk of students, in 1834 Weld organized a debate on slavery which he latter used those students as “agents” for the American Anti-Slavery Society. Weld’s gathering of these students became so successful that they had done away the pamphlet campaign and focused all their resources to enlarge Weld’s “heroic band.” With Seventy “agents” Weld and gave them training in abolitionism for weeks in New York.
Weld, with a voice injury, had taken over the publicity part in which he initiated a new pamphlet campaign, and directed a national campaign in order to get anti-slavery petitions to Congress. Converts, of Welds that were in The House of Representatives, had sent Weld to Washington to act as their advisor. Weld helped secure the thoughts of John Quincy Adams, which led him to serve as Adams assistant in the trial for censure.
While Weld later withdrew from public life his influences were still crucial. His Lobby, continued by Lewis Tappan and Harriet Beecher Stowe had declared that Uncle Tom’s Cabin was formed out of Weld’s most famous tract, American Slavery as it is.