Famous lithograph depicting the attack Wikipedia
Southern Congressman Preston Brooks savagely beat Northern Senator Charles Sumner in the halls of Congress over Sumner's remarks in a speech denouncing slavery. This is a testament to the volatility of U.S. Politics prior to the Civil War and the use of violence was the accepted modus operandi.
After the attack, some Southerners would mail Brooks canes as a show of solidarity for the near lethal beating.