When a congressman beat a senator unconscious, America confronted the limits of free speech

In John Magee’s print, Preston Brooks wields a cane against Charles Sumner, who is clutching a pen and a rolled-up speech. John L. Magee, The New York Public Library

On May 22, 1856, Preston Brooks strode into the United States Senate chamber and beat Sen. Charles Sumner unconscious with a cane. Brooks, a South Carolina congressman, was retaliating for a speech Sumner had given condemning slavery and personally insulting a relative of Brooks.

Though lasting only a minute, the beating had far-reaching consequences. It pushed Americans one step closer to civil war.