The protest was a response to the worst mass killing in U.S. history, the murder of 49 patrons at a gay nightclub in Orlando, Fla., by a person who pledged allegiance to the Islamic State and had been under government surveillance for a time.
While the House held a moment of silence, Democrats said the victims deserved more than platitudes.
"While House Republicans have been silent after the tragedy in Orlando last week, average Americans have not," said Rep. Albio Sires (D-8th Dist.). "Our constituents are demanding action, not inaction. We can no longer shrug our shoulders in the wake of gun violence; Congress must summon the courage to act."
Watson Coleman and Sires were joined on the House floor by the other four New Jersey House Democrats and both of the state's U.S. senators.
"It's a peaceful civil response to a do-nothing Congress," said Rep. Bill Pascrell Jr. (D-9th Dist.).
House Speaker Paul Ryan (R-Wis.) called the Democratic protest a "publicity stunt" in an interview on CNN and said the bill would violate the Second Amendment right to gun ownership and noted that the Senate already has blocked the legislation.
"We will not bring a bill that takes away a person's constitutionally guaranteed rights without due process," Ryan told CNN.
From senior members to freshmen, Democratic lawmakers took turns at the podium, bemoaning gun violence and the lack of any action to address the problem.
"Why do I have people in my district where the only safe place for them to sleep is in their bathtub because of gun violence, because of what they suffer from every single day?" said Rep. Donald Payne Jr. (D-10th Dist.).
Senate Democrats last week held up action on legislation funding the Justice Department and other agencies until the Republican leadership in that chamber agreed to hold votes on gun safety, including banning individuals on the terrorist watch list from buying weapons. Senate Republicans blocked action on that legislation Monday.
U.S. Sen. Cory Booker (D-N.J.), who helped lead the Senate filibuster, was one of several members from that chamber who trekked across the Capitol and join House Democrats in their protest.
"The crisis before us necessitates us using our moral imagination in finding new ways to call to the consciousness of our fellow colleagues in Congress and the American public to come together and wind a way to secure our nation," Booker said.
Senate Democratic Leader Harry Reid of Nevada came, as did U.S. Sen. Robert Menendez (D-N.J.), a former member of the House.
"It dramatizes the importance of the issue," Menendez said. "I don't know how many more lives have to be lost."
To pressure House Republicans to act, Rep. Donald Norcross (D-1st Dist.) organized a phone bank at Camden County Democratic Committee headquarters to contact the offices of GOP members.
"Ten days after the Orlando massacre, the House leadership continues to deny us the opportunity to vote on the very legislation that the majority of America wants — a vote on common sense gun safety measures," Norcross said.
A petition to force a vote on the bill to prevent gun sales to suspected terrorists has garnered 181 signatures from House Democrats, including all six from New Jersey.
"What's the possible justification for allowing somebody on the terrorist watch list to buy a gun?" said Rep. Frank Pallone Jr. (D-6th Dist.). "It's a sense of outrage to not allow a vote on such a common-sense measure. We're determined to stay here until the speaker schedules a vote."