Ralph David Abernathy , (born March 11, 1926, Linden, Ala., U.S.—died April 17, 1990, Atlanta, Ga.), black American pastor and civil rights leader who was Martin Luther King’s chief aide and closest associate during the civil rights movement of the 1950s and ’60s.

The son of a successful farmer, Abernathy was ordained as a Baptist minister in 1948 and graduated with a B.S. degree from Alabama State University in 1950. His interest then shifted from mathematics to sociology, and he earned an M.A. degree in the latter from Atlanta University in 1951. That same year he became pastor of the First Baptist Church in Montgomery, Ala., and he met King a few years later when the latter became pastor of another Baptist church in the same city. In 1955–56 the two men organized a boycott by black citizens of the Montgomery bus system that forced the system’s racial desegregation in 1956. This nonviolent boycott marked the beginning of the civil rights movement that was to desegregate American society during the following two decades.

King and Abernathy continued their close collaboration as the civil rights movement gathered momentum, and in 1957 they founded the Southern Christian Leadership Conference (SCLC; with King as president and Abernathy as secretary-treasurer) to organize the nonviolent struggle against segregation throughout the South. In 1961 Abernathy relocated his pastoral activities to Atlanta, and that year he was named vice president at large of the SCLC and King’s designated successor there. He continued as King’s chief aide and closest adviser until King’s assassination in 1968, at which time Abernathy succeeded him as president of the SCLC. He headed that organization until his resignation in 1977, after which he resumed his work as the pastor of a Baptist church in Atlanta. His autobiography, And the Walls Came Tumbling Down, appeared in 1989.