Washington (CNN) Civil rights icon and US Democratic Rep. John Lewis of Georgia made a surprise appearance at this year's "Bloody Sunday" commemorative march in Selma, Alabama, where he delivered an impassioned plea to voters to use the ballot box as "a nonviolent instrument or tool to redeem the soul of America."
Lewis, who had his skull broken by white police officers during the 1965 march across the Edmund Pettus Bridge in Selma, was diagnosed with stage 4 pancreatic cancer in December. At the time, Lewis said he would undergo treatment for the cancer, and speculation swirled about whether the longtime congressman would be able to participate in the 55th anniversary march.
"Fifty-five years ago, a few of our children attempted to march ... across this bridge. We were beaten, we were tear-gassed. I thought I was going to die on this bridge. But somehow and some way, God almighty helped me here," Lewis said in an emotional speech on Sunday at the apex of the bridge. "We must go out and vote like we never, ever voted before."
"I'm not going to give up. I'm not going to give in. We're going to continue to fight. We need your prayers now more than ever before," he said. "We must use the vote as a nonviolent instrument or tool to redeem the soul of America."
The commemorative march pays tribute to the key civil rights protest pushing for voting rights in which participants attempted to walk from Selma to Alabama's capital, Montgomery. One of the pivotal days was March 7, 1965, when 17 people, including Lewis, were hospitalized after being injured by police and dozens more were hurt.
The march has been reenacted many times on its anniversary. In 2015, President Barack Obama marked the 50th anniversary of the march by delivering a speech at the foot of the Edmund Pettus Bridge, and the following year, the marchers received a Congressional Gold Medal, Congress' highest civilian honor.
Speaking by phone to CNN's Ana Cabrera on "Newsroom" after the march Sunday, Lewis said "it was very moving to be back on the bridge today."
"To see hundreds and thousands of young people with their mothers, their fathers, their grandparents, great grandparents, to see black and white people, Hispanics, and others standing together, marching together, walking together, to not forget what happened and how it happened," he said.
Lewis also expanded on his emotional call for unity at the bridge, asserting, "We all live in the same house, that's the American house."
"We got to make America better for all of her people. When no one is left out or left behind, because of their race, their color, because of where they grew up, or where they were born," he said. "We're one people, we're one family."
First elected to represent Georgia's 5th Congressional District, which includes much of Atlanta, in 1986, Lewis is sometimes referred to as "the conscience of the US Congress." He is known for getting into "good trouble," and by his own count, the congressman was arrested more than 40 times during his days of civil rights activism.
On Sunday, Lewis urged attendees of the march to get into some "good trouble" themselves.
"To each and every one of you, especially you young people ... Go out there, speak up, speak out. Get in the way. Get in good trouble. Necessary trouble, and help redeem the soul of America," he said, as marchers echoed his words and cheered him on.
Several Democratic presidential candidates are also participating in the commemorative march, including former New York City Mayor Michael Bloomberg, Pete Buttigieg, the former mayor of South Bend, Indiana, Minnesota Sen. Amy Klobuchar and Massachusetts Sen. Elizabeth Warren.
Asked what gives him hope Sunday, Lewis told CNN that he's "very hopeful and very optimistic that we're going to work everything out."
"It's the feeling that the changes that are continuing to witness in so many different parts of America. And the American people want us to be hopeful, to be optimistic, and to lead them to a better place, to a better time, and that's what we must do."
CLARIFICATION: This story has been updated to reflect the number of people hospitalized following police beatings in the 1965 march.