Noticeably absent from the speaker line-up at the Let Freedom Ring event commemorating the 50th anniversary of the March on Washington today: the nation's only black Senator, Tim Scott.

Scott, a Republican Representative appointed by S.C. Governor Nikki Haley earlier this year to fill former Sen. Jim DeMint's seat in the U.S. Senate after he retired, was not invited to participate in the historic event, a spokesperson for the Senator confirmed to Red Alert Politics in an email.

African-American leaders who did receive an invitation to speak at included Rep. John Lewis (D-Ga.) - who participated in the original March - Martin Luther King III, MSNBC host Al Sharpton and movie stars Jamie Foxx, Oprah Winfrey and Forest Whitaker.

Update: Talking Points Memo is reporting that a source involved in planning the March on Washington says Scott wasn't invited because he declined to attend the event as a spectator.