SELMA, Ala. — Vice President Joe Biden and black leaders commemorating a famous civil rights march on Sunday said efforts to diminish the impact of African-Americans’ votes haven’t stopped in the years since the 1965 Voting Rights Act added millions to Southern voter rolls.

More than 5,000 people followed Biden and US Representative John Lewis, Democrat of Georgia, across the Edmund Pettus Bridge in Selma’s annual Bridge Crossing Jubilee. The event commemorates the ‘‘Bloody Sunday’’ beating of voting rights marchers — including a young Lewis — by state troopers as they began a march to Montgomery in March 1965.