US President Barack Obama speaks during the Let Freedom Ring Commemoration and Call to Action to commemorate the 50th anniversary of the March on Washington for Jobs and Freedom at the Lincoln Memorial in Washington, DC on August 28, 2013. The March on Washington is best remembered for King’s stirring vision of a United States free of inequality and prejudice, telecast live to a nation undergoing a phenomenal decade of soul-searching, crisis and change. AFP Photo/Jewel Samad (Photo credit should read JEWEL SAMAD/AFP/Getty Images)