On April 9, 1939 an historic musical event took place on the National Mall in Washington, D.C. On the steps of the Lincoln Memorial, Marion Anderson sang to an audience of 75,000 people after being denied access to Constitution Hall by the DAR (who owned the Hall) because of their white-only artist policy. Years later, Marion Anderson did sing at Constitution Hall; by that time the DAR had apologized and had changed its rules. https://www.youtube.com/watch?v=mAONYTMf2pk