March on Washington: Throngs mark 'I Have a Dream' anniversary

(CNN) -- Prayers calling for strength under adversity, celebration of freedom and a fair share of the country's resources kicked off a rally Saturday on the National Mall marking the 50th anniversary of the historic March on Washington.

The August 28, 1963, march made "I have a dream" the clarion call of the civil rights movement.

Speakers addressed a crowd of thousands that will later march past the King Memorial, where an image of the slain civil rights leader now stands immortalized in granite.

Calls for reversing the country's growing income inequality were repeated by several speakers, as were promises to continue to carry the torch of civil rights.

More than one speaker invoked the killing of Trayvon Martin as an example of where they see lack of justice for African-Americans.

In 1963 "we could not have imagined we'd be here 50 years later with a black president and a black attorney general, but that's a measure of how far we have come," civil rights activist Julian Bond said. "But still, we march."

Minorities have never wished their way to freedom, he said, but have worked their way up, and must continue to do so.

Kathleen Johnson and Jean McRay were at the first March on Washington 50 years ago, and as the crowd grew on Saturday, they reflected on the span in between.

"It was a wonderful experience (in 1963) because prior to that there were many things going on in the United States that were not right," Johnson said.

The injustices that existed in 1963 convinced Johnson and her family and friends to attend the march.

"We had to be there. We had to be a part of it," she said.

The fight for equality that the original march embodied remains a work in progress, McRay said, which makes Saturday's event so important.

"We need this, especially now," she said.

Both women wore buttons from the march in 1963.

Saturday's event is the first of two rallies to mark the anniversary.

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

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.