As we watch history unfolding before our eyes, one more anniversary: It was almost seventy years ago, on Easter Sunday in 1939, that more than 75,000 people come to the Lincoln Memorial in Washington, D.C., to hear famed African-American contralto Marian Anderson give a free open-air concert.

Anderson had been scheduled to sing at Washington's Constitution Hall, but the Daughters of the American Revolution, a political organization that helped manage the concert hall, denied her the right to perform because of her race. The first lady, Eleanor Roosevelt, resigned her membership from the organization in protest, and Anderson's alternate performance at the Lincoln Memorial served greatly to raise awareness of the problem of racial discrimination in America.