In the latter part of May, 1856, Mr. Sumner was assailed in his seat in the Senate chamber by Mr. Brooks of South Carolina, and beaten over the head with a cane until he fell unconscious upon the floor, covered with blood. When the assault was made, General Wilson was in the room of Speaker Banks engaged in conversation with several members of the House. Returning to the Senate Chamber, he found his friend and colleague almost unconscious in the hands of his friends. He aided in the sad task of bearing him to his chamber and placing him on his couch of pain. That night the Republican members met at the house of Mr. Seward, and commissioned General Wilson to call the attention of the Senate to the assault upon his colleague, which duty he performed next day in a few very appropriate words. On motion of Mr. Seward, a committee was appointed, and on the morning of the 27th, Mr. Slidell, Mr. Toombs, Mr. Douglas and others rose to make some personal explanations concerning the statement made to the committee by Mr. Sumner. The floor and galleries were crowded, and every word was listened to with the most intense interest. General Wilson rose to defend his absent colleague, who was confined to his room, as he declared, from the effects "of a brutal, murderous, and cowardly assault." He was instantly interrupted by an exclamation from Mr. Butler, and cries of order increased the intense excitement which prevailed in the crowded chamber. Threats of personal violence were made by Mr. Brooks' friends, and several members of both houses assured General Wilson that they would stand by him in any emergency. That evening, after the adjournment of Congress, he was compelled to leave Washington for Trenton, to address the Republican State convention of New Jersey. On his return, on the morning of the 29th, he was called upon by General Lane, of Oregon, and a challenge from Mr. Brooks placed in his hands. General Wilson promptly responded by placing in the hands of General Lane, through his friend, Mr. Buffinton, the following note:
Washington, May 29, 10½ o'clock.
"Hon. P. S. Brooks,
"Sir: Your note of the 27th inst. was placed in my hands by your friend General Lane, at twenty minutes past ten o'clock to-day.
"I characterized, on the floor of the Senate, the assault upon my colleague as 'brutal, murderous, and cowardly.' I thought so then, I think so now. I have no qualifications whatever to make in regard to those words.
"I have never entertained or expressed in the Senate or elsewhere, the idea of personal responsibility in the sense of the duellist.
"I have always regarded duelling as the lingering relic of a barbarous civilization, which the law of the country has branded as a crime. While, therefore, I religiously believe in the right of self-defence in its broadest sense, the law of my country and the matured convictions of my whole life alike forbid me to meet you for the purpose indicated in your letter.
"Your obedient servant,
"Henry Wilson."
This prompt and emphatic response, declining to fight a duel, but at the same time avowing his readiness to maintain the right of self-defence, was most enthusiastically approved and applauded by the people and presses of the North, and he received many letters, from men of the highest character, warmly commending his noble and dignified course.