After serving as a clerk for Justice Howard M. Stephens of the United States Court of Appeals for the District of Columbia in 1943, King returned to Utah.

From 1948 to 1958, King was the second assistant to Elbert R. Curtis, who was the ninth General Superintendent of the LDS Church's Young Men's Mutual Improvement Association.

He was appointed United States Ambassador to Madagascar and to Mauritius in January 1967 and in May 1968, respectively, serving in those two positions concurrently until August 1969.

During the 1970s and 1980s, King practiced law in Washington, D.C., and served as an alternate director at the World Bank.

[5][6] King was a direct patrilineal descendant of Edmund Rice, an English immigrant to Massachusetts Bay Colony, as follows:[7]