Final answer:
Senator Charles Sumner was the victim of a brutal cane attack by Representative Preston Brooks in the Senate, which exacerbated sectional tensions and underscored the conflict over slavery and free speech in the United States.
Step-by-step explanation:
The victim of a violent attack in the Senate by a southern congressman was Massachusetts senator Charles Sumner. On May 22, 1856, Representative Preston Brooks of South Carolina violently assaulted Sumner with a cane in the Senate chamber, after Sumner made dereogatory remarks about Brooks' cousin, Senator Andrew Butler, and the institution of slavery. The attack was celebrated by some southerners as a defense of their honor and the honor of South Carolina, highlighting the intense sectional divisions of the time. Northerners, on the other hand, saw Sumner as a martyr for the antislavery cause, evidencing the barbarity of slavery and the suppression of free speech.