Throngs to attend events, mark 'I Have a Dream' anniversary

(CNN) -- Throngs are expected on the Washington Mall on Saturday for the first of two rallies marking the 50th anniversary of the march that made "I Have a Dream" the clarion call of the civil rights movement.

President Barack Obama headlines another event Wednesday, the exact anniversary of the Aug. 28, 1963, "March on Washington," where Martin Luther King Jr. delivered the now-famous speech at the Lincoln Memorial.

Saturday's event begins with speeches before a march past the King Memorial, where an image of the slain civil rights leader now stands immortalized in granite.

Scheduled speakers Saturday include Rep. John Lewis, who was among the speakers preceding King in 1963, and two of King's children, Bernice King and Martin Luther King III.

The Rev. Al Sharpton, an organizer of Saturday's event, said marchers will demand more work on issues such as poverty, health care and voting rights.

"It is the intent of those that come together to make it clear that this is not just a nostalgia visit, that this is not a commemoration but a continuation and a call to action," Sharpton said in a statement. "We are in a climate that is threatening too much of what was achieved 50 years ago."

The Wednesday event will include a longer march through Washington and speeches by Obama and former presidents Bill Clinton and Jimmy Carter.