The information in this paragraph is from the US House historian’s website. [1]Archived 2011-07-23 at the Wayback Machine
jstor.org
James M. McPherson, "The Fight Against the Gag Rule: Joshua Leavitt and Antislavery Insurgency in the Whig Party, 1839–1842." Journal of Negro History (1963): 177–195 in JSTOR.