When the conflicts in Kansas Territory known as Bleeding Kansas erupted in 1855–1856, Yancey spoke publicly in support of Jefferson Buford's efforts to raise 300 men to go to Kansas and fight for Southern interests. In 1856, Yancey was head of the platform committee for the state Democratic and Anti–Know Nothing Convention, and he succeeded in having the convention readopt the Alabama Platform. In June 1856, he participated in a rally condemning Charles Sumner while praising his assailant Preston Brooks, who nearly bludgeoned Sumner to death in the United States Senate chamber. In June 1857, Yancey spoke at a rally opposing Robert J. Walker's actions as territorial governor of Kansas. In July 1856, he spoke at the University of Alabama's graduation on "the distinctive characteristics of the Northern and Southern people of the Union." In January 1858, he participated in a rally supporting William Walker, the famous Nicaragua filibuster, calling the "Central American enterprise as the cause of the South."