At the dedication of the Lincoln Memorial on May 30, 1922, the black spectators who showed up early to be present up front were all cleared out and moved to roped-off segregated seating in the rear. One historian noted that instead of emancipation being the focus, it was the reunification of the North and the South.
This is the centennial of that dedication.
Simple answer? Racism is passed on - like religion. It stays with you for generations.
George Stephanopoulos once remarked that the gay issue has been resolved because young people don't have a problem with it. It's just a matter of the older people that do dying off.
Historian Harold Holzer talks about the centennial.