Representative John Lewis, a son of sharecroppers and an apostle of nonviolence who was bloodied at Selma and across the Jim Crow South in the historic struggle for racial equality, and who then carried a mantle of moral authority into Congress, died on Friday. He was 80.

His death was confirmed in a statement by Nancy Pelosi, the speaker of the House of Representatives.

Mr. Lewis, a Georgia Democrat, announced on Dec. 29 that he had Stage 4 pancreatic cancer and vowed to fight it with the same passion with which he had battled racial injustice. “I have been in some kind of fight — for freedom, equality, basic human rights — for nearly my entire life,” he said.