Obama saluted King as a man who “stirred our conscience” and made the Union “more perfect,” and rejoiced in the memorializing of the slain civil rights leader’s life and work. (AP Photo/Charles Dharapak)

President Barack Obama, walks hand-in-hand with daughter Malia as he is followed by (L-R) first lady Michelle Obama, Harry Johnson, president and CEO of the MLK National Memorial Project Foundation, Andrea King carrying daughter Yolanda, and Michelle Obama’s mother Marian Robinson. (Photo by Mike Theiler-Pool/Getty Images)

President Barack Obama, flanked by daughters Sasha (L) and Malia® examine a time capsule along with first lady Michelle Obama (2nd,R) and Michelle’s mother Marian Robinson as they arrive for the dedication of the Martin Luther King, Jr Memorial on the National Mall. (Photo by Mike Theiler-Pool/Getty Images)

President Barack Obama, walks hand-in-hand with daughter Malia as he is followed by (L-R) first lady Michelle Obama, Harry Johnson, president and CEO of the MLK National Memorial Project Foundation. (Photo by Mike Theiler-Pool/Getty Images)

Singer Aretha Franklin® accepts applause as she finishes her performance with U.S. President Barack Obama, first lady Michelle Obama and Harry Johnson, president and CEO of the MLK National Memorial Project Fund (L) as they attend the dedication of the Martin Luther King, Jr Memorial. (Photo by Mike Theiler-Pool/Getty Images)

Al Sharpton speaks during the Martin Luther King, Jr. Memorial dedication on the Main Stage at West Potomac Park on October 16, 2011 in Washington, DC. (Photo by Kris Connor/Getty Images)

Singers Stevie Wonder, left, and Ledisi perform a duet at the dedication of the Martin Luther King, Jr., Memorial, in Washington, Sunday, Oct. 16, 2012. (AP Photo/Cliff Owen)

Rev. Al Sharpton arrives ahead of President Barack Obama speaking at the dedication of the Martin Luther King Jr. Memorial in Washington, Sunday, Oct. 16, 2011. (AP Photo/Charles Dharapak)

Standing beneath an image of her brother behind her, Dr. Christine King Farris speaks at the dedication of his memorial, the Martin Luther King, Jr., Memorial, in Washington, Sunday, Oct. 16, 2012. (AP Photo/Cliff Owen)

Standing beneath an image of his father, Martin Luther King, III, speaks at the dedication of the Martin Luther King, Jr., Memorial, in Washington Sunday, Oct. 16, 2012. (AP Photo/Cliff Owen)

Edna Washington, of Memphis, Tenn., holds up a portrait of Martin Luther King, Jr. during the dedication of the Martin Luther King, Jr., Memorial, in Washington, Tuesday, Oct. 16, 2012. (AP Photo/Cliff Owen)

Aretha Franklin sings during the dedication ceremony for the Martin Luther King Jr. Memorial Sunday, Oct. 16, 2011, on the National Mall in Washington. (AP Photo/Carolyn Kaster)

Aretha Franklin arrives to sing at the dedication ceremony for the Martin Luther King Jr. Memorial Sunday, Oct. 16, 2011, on the National Mall in Washington. (AP Photo/Carolyn Kaster)

Andrew Young speaks during a dedication ceremony at the Martin Luther King Memorial on the National Mall October 16, 2011 in Washington, DC. (Photo by Brendan Smialowski/Getty Images)

Jesse Jackson speaks during the Martin Luther King, Jr. Memorial dedication on the Main Stage atWest Potomac Park on October 16, 2011 in Washington, DC. (Photo by Kris Connor/Getty Images)

President Barack Obama, center, his daughter Malia Obama, left, and Harry Johnson, President and CEO of the Martin Luther King Jr. Memorial Foundation, to his right, look up at the Martin Luther King Jr. Memorial. (AP Photo/Carolyn Kaster)

Singer Jennifer Holliday performs during a dedication ceremony at the Martin Luther King Memorial on the National Mall October 16, 2011 in Washington, DC. (Photo by Brendan Smialowski/Getty Images)

Singer Sheryl Crow performs during a dedication ceremony at the Martin Luther King Memorial on the National Mall October 16, 2011 in Washington, DC. (Photo by Brendan Smialowski/Getty Images)

Elder Bernice King, daughter of Martin Luther King Jr., speaks during a dedication ceremony at the Martin Luther King Memorial on the National Mall October 16, 2011 in Washington, DC. (Photo by Brendan Smialowski/Getty Images)

Designer Tommy Hilfiger speaks during a dedication ceremony at the Martin Luther King Memorial on the National Mall October 16, 2011 in Washington, DC. (Photo by Brendan Smialowski/Getty Images)