Lyon was later imprisoned under the Alien and Sedition Acts and won reelection from his prison cell.
Graves was a hunter, Cilley a city boy with little knowledge of guns. Graves shot Cilley dead on the Bladensburg dueling grounds.
It took Sumner three years to recover from the attack. Because Brooks broke his cane beating Sumner, Southerners responded by sending Brooks dozens of replacement canes. A Virginia newspaper wrote of the attack, "We consider the act good in conception, better in execution, and best of all in consequences. These vulgar abolitionists in the Senate must be lashed into submission."
The House Brawl
Congressman Laurence Keitt (the coward who held the gun during the Sumner attack) and Pennsylvania's Galusha Grow got into a shouting match on the House floor. It devolved into a fistfight which, in turn, fell into an all out brawl. The subject, of course, was slavery.
A couple years later (Dec. 1860) Grow challenged a North Carolina congressman to a duel but police arrested all the participants before anything happened.
The Gallery Gunman
In 1932, a Sears sporting goods clerk brandished a gun from the visitors gallery and demanded the right to speak about the Depression. He was talked into surrendering the gun by Congressman Melvin Maas. No one was hurt but the gun was loaded so it makes the list.
Puerto Rico Nationalists
In 1954, four Puerto Ricans fired automatic pistols from the gallery. Five congressmen were wounded; none killed.
In the early 1950's the United States converted Puerto Rico from a colony into a "commonwealth state." The feeling among nationalists at the time is that commonwealth was just another word for colony. The United States was brutal in suppressing rebellious Puerto Ricans. In Utuado, insurgents who surrendered were machine gunned. The leader of the revolt was tortured in prison.
Photo found here.Nationalists retaliated by attacking Congress and attempting to assassinate President Truman.
Congressman Leo Ryan led a team of officials and reporters to Jonestown to examine condition and help any Americans who wanted to go home. Only 14 of nearly 1000 people wanted to leave Jim Jones' commune but that was too many. When they got to the landing strip the Ryan delegation was attacked by Jones loyalists. Congressman Ryan was among the five dead.
Back at Jonestown, Jim Jones convinced his flock to commit mass suicide.
History has seen other Congressional brawls plus the deaths of several other people who were not at the time sitting members of Congress including police officers, a non-voting delegate, and a former congressman. But, only two congressmen have died violently while in office. Given our violent history, that is amazing.