• Pro-slavery congressman Preston Brooks attacked antislavery Senator Charles Sumner on floor of Senate
• Violence of attack hinted at Civil War to come

22 May 1856 may have been the worst day in the history of the United States Senate. Late that afternoon, after both houses had recessed for the day, a young South Carolina congressman named Preston Brooks strode forcefully into the Senate chamber looking for Massachusetts Senator Charles Sumner. The Senate floor was nearly deserted, but Brooks saw Sumner sitting alone at his desk, preparing a stack of pamphlets for mailing.

Without warning, Brooks rushed forward and began beating the unsuspecting Sumner savagely with a gold-tipped wooden cane. Even after knocking the older man to the ground, Brooks continued raining down blows upon Sumner's bleeding head and defenseless body, only stopping when his cane shattered into pieces. Finally, after perhaps the most shocking few minutes in the history of Congress, Brooks turned and walked calmly out of the chamber, leaving Sumner bloodied and unconscious.

Charles Sumner nearly died of the wounds he suffered that day. And though he eventually regained consciousness and returned—following three years spent recovering from his injuries—to the Senate, he suffered for the rest of his life from intense headaches and what we would now call post-traumatic stress disorder.

Preston Brooks resigned from the House but was almost immediately returned to office by his South Carolina constituents, who viewed his actions as those of a hero.

What in the world could cause such an eruption of naked violence right there on the floor of "the world's greatest deliberative body?"

The answer is slavery. Or, to be more precise, an increasingly destructive debate over the future of slavery—a debate which would soon lead to the Civil War.

Charles Sumner was one of the most outspoken opponents of slavery in all of Congress. Three days before his beating, he delivered a speech on the Senate floor, bitterly attacking other senators who favored allowing slavery to spread into Kansas and other new territories in the West. In the speech, Sumner likened slavery to a "harlot" and described a pro-slavery senator as a "noise-some, squat, and nameless animal." These were harsh words, obviously, but Sumner felt that he spoke on the side of righteousness against a grave moral evil, and he had no patience for slavery's defenders in the Senate.

Preston Brooks was the cousin of one of the senators Sumner had insulted. And according to his own moral code, a code deeply rooted in the cultural traditions of the South, honor required that such an insult could not go unanswered. Thus he decided to teach Charles Sumner a lesson—a lesson taught in blood.

The United States Senate has always prided itself on its tradition of unlimited debate. But the Sumner-Brooks affair proved that, by the mid-1850s, there were very real limits on what could be safely debated in Congress—or anywhere in America. The issue of slavery had become more and more explosive, and the fact that its discussion—even on the floor of the Senate—led to outright violence was a very ominous sign for the country as a whole.

In a sense, the awful spectacle of the Sumner-Brooks Affair was only a preview of the nightmarish violence that was to come; almost exactly five years after Preston Brooks beat Charles Sumner to within an inch of his life, Union and Confederate soldiers faced off in the first battles of the Civil War, by far the bloodiest conflict in American history.

The issue that could not be safely debated in the United States Senate nearly destroyed the United States itself. Charles Sumner was, in a sense, the first casualty of the Civil War.