COLUMBIA, S.C. - (AP) - President Barack Obama says this weekend's 50th anniversary commemoration of historic civil rights marches is as much about stirring young people to change as about honoring yesterday's legends, calling the push for "a fair and more just criminal justice system" part of the modern struggle.

Obama is leading Saturday's tribute in Selma, Alabama, where where 50 years ago police beat scores of people who were marching from Selma to Montgomery to protest their lack of voting rights. The marches helped lead to passage of the Voting Rights Act of 1965.

"Selma is not just about commemorating the past, it's about honoring the legends who helped change this country through your actions today, in the here and now," Obama said at a town hall meeting at South Carolina's Benedict College. "Selma is now."