On May 22, 1856, congress became a combat zone. In one of the most dramatic and deeply ominous moments in the Senate's entire history, a member of the House of Representatives entered the Senate Chamber and savagely beat a senator into unconsciousness.

From 1830 to 1860, there were over 70 accounts of violence in Congress. It was a time of heightened tensions, especially over slavery. Congressmen during this period commonly carried pistols or bowie knives when they stepped onto the congressional floor. In fact, by the late 1850s, some voters actually sent their congressmen guns to remind them to defend their state’s interests.

One of the most famous accounts of violence was called the “Caning of Sumner.” After the sack of Lawrence, on May 21, 1856, Senator Sumner gave a bitter speech in the Senate called "The Crime Against Kansas." He blasted the proslavery "murderous robbers from Missouri," and personally attacked South Carolina's Senator Andrew Butler. Sumner declared Butler a fool for supporting slavery. Butler’s cousin, Preston Brooks, felt he needed to defend his family’s honor. After getting sufficiently drunk one day, the pro-slavery southerner Brooks walked over to Senator Charles Sumner and beat the anti-slavery northerner unconscious with a cane.

Bleeding profusely, Sumner was carried away. Brooks walked calmly out of the chamber without being detained by the stunned onlookers. Overnight, both men became heroes in their respective regions. In the North, Sumner was considered a martyr. Outraged northerners claimed Brooks’ actions showed that slavery made southerners into violent criminals. In the South, Brooks was considered a hero who defended the honor of the South. His supporters sent him hundreds of canes, some gold plated, in support of his actions.

Surviving a House censure resolution [a formal reprimand], Brooks resigned, was immediately reelected, and soon thereafter died at age 37 of a throat infection that was so bad he ripped his throat open with his bare hands in an attempt to catch a breath. Sumner recovered slowly and returned to the Senate, where he remained for another 18 years. The nation, suffering from the breakdown of reasoned discourse that this event symbolized, tumbled onward toward the catastrophe of civil war.