- Rep. John Lewis is leading a sit-in on the House floor
- He's calling for action on gun control legislation
- Lewis is a Civil Rights icon who marched with Dr. Martin Luther King Jr.
(CNN)Democratic Rep. John Lewis is sitting back down.
This time, he's on the floor of the House of Representatives to demand action on gun control legislation.
"We're going to continue to sit in and sit down," he said Wednesday night. "By sitting in and sitting down, we're standing up."
"We will not be happy, we will not be satisfied, we will not be pleased until we do something in a major way," he said early Thursday morning. "We've lost too many of our children, of our babies, too many of our mothers and fathers, our brothers and sisters. And we will continue to fight."
The sit-in is a tried and tested form of protest for Lewis, 76, who represents part of Atlanta in Congress.
He is Civil Rights icon -- a former freedom rider, a Bloody Sunday survivor and the last living keynote speaker from the 1963 March on Washington. And he knows how to fight for a cause.
Though his previous sit-ins did not produce immediate results, the years of nonviolent protests Lewis organized and participated in are considered driving factors that helped drum up support for the passage of the Civil Rights Act.
Decades of advocacy
Lewis became involved in the Civil Rights movement at 15 years old.
"I heard the words of Martin Luther King Jr. on our radio and I heard about Rosa Parks" he said in 2014. "It seemed like Martin Luther King Jr. was speaking directly to me, saying John Lewis, you too can do something. You can make a contribution."
He began organizing sit-ins at segregated lunch counters in the Nashville area in college while studying at Fisk University.
Lewis then participated in the Freedom Rides in 1961, protesting segregation at interstate bus terminals by sitting in seats reserved for white customers.
At 25, Lewis marched with King from Selma to Montgomery, and was on the Edmund Pettus Bridge on Bloody Sunday, where he was beaten by police and knocked unconscious.
"I gave a little blood on that bridge," he said. "I thought I was going to die. I thought I saw death."
Fifty years later, at an event to commemorate the incident, he spoke before President Barack Obama on the bridge, just feet away from where he was nearly killed.
"We must use this moment to recommit ourselves to do all we can to finish the work -- there's still work left to be done," he said.
Early Tuesday, he made reference to the Edmund Pettus Bridge again.
"It took us three times to make it all the way from Selma to Montgomery," Lewis said Thursday morning. "We have other bridges to cross."
Bloody Sunday is considered a turning point in the Civil Rights movement -- Americans from around the country watched in horror as they saw peaceful protesters tear gassed, trampled and beaten on television.
It also spurred President Lyndon B. Johnson's historic speech before Congress.
"It is wrong -- deadly wrong -- to deny any of your fellow Americans the right to vote in this country," Johnson said. "It's all of us who must overcome the crippling legacy of bigotry and injustice. And we shall overcome."
Lewis watched the speech with Dr. King. He told CNN that Johnson was the first American president to use that phrase -- the theme song of the Civil Rights Movement.
"I looked at Dr. King, tears came down his face. I started crying a little," Lewis said.
Decades later, the cause is different but the song remains the same -- "We Shall Overcome" could be heard on the House floor late Wednesday evening.