What prompted this speech by sumner to congress in 1856?

Charles Sumner was prompted to deliver his famous "Crime against Kansas" speech because the circumstances under which the pro-slavery movement had manipulated the Kansas convention in order to come out with a pro-slavery group of constituents who would then determine that Kansas would enter into the union of the United States as a slave state, which would undermine and set off balance views that were contrary to what Charles Sumner aligned himself, with the abolitionist movement to eliminate or abolish slavery.

February 1848 is when it was added. if that's what you were asking