In August 1963 , King spoke of President Lincoln and his well-known words : `` Five score years ago , a great American , in whose symbolic shadow we stand today , signed the Emancipation Proclamation . Standing on the steps of the Lincoln Memorial in August 1963 , King began with a reference to President Lincoln and his enduring words : `` Five score years ago , a great American , in whose symbolic shadow we stand today , signed the Emancipation Proclamation .