Franklin Pierce’s toughest challenge as President was the passage of the Kansas-Nebraska Act in 1854. This act repealed the Missouri Compromise and, in the west, reopened the question of slavery. These and more triggered a series of events known as "Bleeding Kansas". Pro-slavery Border Ruffians, mostly from Missouri, illegally voted in a government. Pierce recognized this and called the Topeka Constitution, set up by Free-Staters, as an act of “rebellion.” Overall, Franklin Pierce is ranked among the least effective Presidents of the United States, as he was unable to steer a steady, prudent course.