Why were the 40th Academy Awards postponed for two days?

The 40th Academy Awards honored film achievements of 1967. Originally scheduled for April 8, 1968, the awards were postponed to two days later, April 10, 1968, because of the Assassination of Martin Luther King Jr. King was an American clergyman and civil rights leader was shot at the Lorraine Motel in Memphis, Tennessee, on April 4, 1968. King was rushed to St. Joseph's Hospital and was pronounced dead at 7:05 p.m. CST. He was a prominent leader of the Civil Rights Movement and a Nobel Peace Prize laureate who was known for his use of nonviolence and civil disobedience. Bob Hope was once again the host of the ceremony.

This year's nominations also marked the first time that three different films were nominated for the "Top Five" Academy Awards: Best Picture, Director, Actor, Actress and Screenplay. The three films were Bonnie and Clyde, The Graduate and Guess Who's Coming to Dinner. However, the winner of Best Picture was producer Walter Mirisch and director Norman Jewison's thriller/mystery film, In the Heat of the Night (with seven nominations and five wins – Best Picture, Best Actor, Best Screenplay, Best Film Editing and Best Sound).