Martin Luther King Jr. had two siblings: an older sister called Willie Christine and a younger brother called Alfred Daniel Williams King, or A. D. for short. Willie Christine was born on September 11, 1927, Martin Luther on January 15, 1929, and A. D. on July 30, 1930.

Both of King's siblings joined with him in the struggle for civil rights. Willie Christine—or Willie Christine King Farris as she's been known since her marriage—has been involved in civil rights organizations such as the NAACP and the Southern Christian Leadership Conference, whose first president was her younger brother Martin.

A. D. King, like his older brother, was a Baptist minister. He participated in some of the most important campaigns of the civil rights movement, such as the Birmingham campaign, which openly challenged segregation in the state of Alabama. He was also involved in sit-ins of segregated lunch counters.

After Martin Luther King's assassination, A. D. developed a serious drinking problem as well as depression. It is believed by some that his brother's murder, as well as his ongoing battle with alcohol and depression, contributed to a weakening of his heart, which may well have been a factor in his death by drowning just over a year after his brother's untimely death.

After spending nearly half a century as a professor at Spelman College, a Black liberal arts college for women, Willie Christine Farris King retired in 2014. On September 11 of this year, she celebrated her ninety-third birthday.