Democrat lawmakers relied on social media to transmit videos and pictures of their sit-in using Facebook, Twitter and Periscope.
Democrats shut down the House of Representatives' legislative work on Wednesday, staging a sit-in on the House floor and refusing to leave until they secured a vote on gun control measures before lawmakers' week-long break.
Chanting "No bill, no break!" scores of Democrat lawmakers joined in the protest which follows the Orlando mass shooting.
A similar incident took place in August 2008, when House Republicans, then in the minority, took the floor to demand a vote on allowing offshore drilling.
"We are in for the long haul here," House Democrat leader Nancy Pelosi told reporters, saying members intended to continue their sit-in as long as it takes to get a vote on a bill.
She said the House needs to act on gun legislation, rather than continually hold moments of silence in memory of victims of gun violence.
The demand for legislation echoed last week's filibuster by Senate Democrats to protest inaction on guns in the wake of the June 12 massacre at a gay nightclub in Orlando, Florida. At least 49 people were killed and 53 others wounded in the deadliest mass shooting in modern US history.
The Orlando shooter, Omar Mateen, 29, pledged allegiance to DAESH during the rampage in which he used an assault rifle and pistol.
Authorities believe Mateen, a US citizen of Afghan descent, was self-radicalised and acted alone with no help from militant networks.
After the Senate talk-a-thon, the Senate's Republican majority scheduled votes on four gun control measures - all of which failed on Monday.
'Quiet too long'
The protest was led by Representative John Lewis, a Democrat from Georgia and veteran of the 1960s civil rights movement.
"We have been too quiet for too long," Lewis told fellow lawmakers. "We will be silent no more."
"American people demand an action.....We can no longer wait, we can no longer be patient, so today we come to the house to dramatise the need for action."
Democrats urged gun control measures such as tighter background checks and legislation to curb the sale of weapons to people on government watch lists.
For as long as there are no votes on gun legislation, Representative Jerrold Nadler of New York declared: "The blood is on the leadership of this House."
Democrats cited polls showing broad public support for expanding background checks for firearms purchases and blocking suspected terrorists from buying guns.
A number of Democrat senators including Senators Elizabeth Warren, Tim Kaine, Cory Booker and Bernie Sanders also joined the protesters.
Exasperated Republicans were forced to take a recess while cutting off cameras that showed the protest.
Democrats broadcast sit-in on social media
Later, Democrat lawmakers relied on social media to transmit videos and pictures using Facebook, Twitter and Periscope.
John Lewis tweeted: "Sometimes you have to get in the way. You have to make some noise by speaking out against injustice and inaction."
Sometimes you have to get in the way. You have to make some noise by speaking up and speaking out against injustice & inaction #goodtrouble— John Lewis (@repjohnlewis) June 22, 2016
Tweets of support came from outside Congress. "Thank you John Lewis for leading on gun violence where we need it most," President Barack Obama tweeted.
Thank you John Lewis for leading on gun violence where we need it most. https://t.co/vctfqAH5Wt— President Obama (@POTUS44) June 22, 2016
Former US president Bill Clinton tweeted: "This is leadership."
US Democrat presidential candidate Hillary Clinton tweeted:"This is what real leadership looks like."
This is what real leadership looks like. https://t.co/4Nh6QpqSxL— Hillary Clinton (@HillaryClinton) June 22, 2016
Democrats also posted the Capitol's main telephone number, which was overwhelmed, and urged constituents to call and request a vote.
Guns are a controversial political issue.
Congress has not passed major gun control legislation since 1994, with gun rights defenders saying such measures infringe on the constitutional right to bear arms.
The House's presiding officer, Republican Representative Ted Poe, entered the chamber to find a number of Democrat lawmakers in the front of the chamber.
After banging the gavel several times in an unsuccessful attempt to clear the protesters, Poe announced the chamber would be in recess and left.
But the Democrat protesters stayed in the chamber for an afternoon of speeches, calling for action before a break scheduled to begin this weekend through July 5.
Republican House Speaker Paul Ryan refused to give in to what he called a "publicity stunt" and vowed not to bring up any bill that would take away anyone's right to own firearms.