Representative Sander Levin of Michigan called it a "Selma-like moment."
Representative Joe Kennedy of Massachusetts, reading a letter from the wife of a slain Boston doctor, said that after Orlando, she has cried every day.
An extraordinary sit-in on the House floor began on Wednesday morning, with Democrat after Democrat demanding that the House vote on a gun-control bill before going on recess.
It went on into Thursday morning, even after the Republicans voted to go on recess until July 5. It had continued long after House Republican leaders on Wednesday shut down the microphones and the House cameras, but C-SPAN began running a Periscope video stream to broadcast it to the nation for hours.
Inside nearly every Democrat who spoke thanked Rep. John Lewis of Georgia, who organized civil rights protests throughout the 1960s, including the Selma march, and was a leader of this protest. Republicans dismissed the action as a stunt; Lewis, 76, called it "good trouble" needed to push Congress into action, and led chants of "No bill, no break!" throughout the sit-in.
President Obama singled out Lewis on Twitter, saying: "Thank you John Lewis for leading on gun violence where we need it most."
Before dawn, Lewis said the push for gun-control bills will resume when the House reconvenes. Democrats kept speaking in the chamber for hours afterward.
The Democrats wanted a vote on bills to prevent guns from being sold to suspected terrorists and to expand background checks, both opposed by the powerful National Rife Association.
"Can't we come to the table? Can't we have a discussion? Can't we say enough is enough?" asked Representative Debbie Dingell of Michigan, who gave an impassioned speech about being threatened with a gun when growing up.
Outside the Capitol late Wednesday, hundreds of people thronged in support of the revolt and the effort to vote on gun control, just days after the worst mass shooting in modern US history.
The protest, in which members told stories of constituents who died in gun violence, amounted to a very long challenge to House Republicans to move. It enabled Democrats to label the Republicans as controlled by the NRA lobbying group. House Speaker Paul Ryan came under incessant criticism, both from his congressional colleagues and the New York Daily News.
Some Democrats pledged to sit as long as it takes. “I don’t know how many of us or all of us are going to stay,” said Representative Jan Schakowsky of Illinois. “But my plan is I have a blankey.”