Wednesday’s day of tributes starts at the White House, where Obama is to present the Presidential Medal of Freedom to more than a dozen prominent Americans in fields ranging from politics and entertainment to sports and science. Former President Bill Clinton, Oprah Winfrey and the late astronaut Sally Ride are among this year’s recipients.

Kennedy established the modern version of the medal, the highest award the U.S. gives a civilian, but he didn’t live to make that first presentation. He was fatally shot by Lee Harvey Oswald in Dallas on Nov. 22, 1963, two weeks before he planned to honor the inaugural group of recipients. Hundreds since have received the medal....