epa03840869 Spectators watch President Barack Obama speak at the 'Let Freedom Ring' commemoration at the Lincoln Memorial in Washington DC, USA, 28 August 2013. The commemoration marks the 50th anniversary of the 28 August 1963 March on Washington led by the late Dr. Martin Luther King Jr., where he famously gave his 'I Have a Dream' speech. EPA/JIM LO SCALZO