Born in Syracuse, New York, King received a Bachelor of Arts degree, summa cum laude, from Smith College in 1959.

[2] King was nominated by President Jimmy Carter on April 30, 1979, to the United States Court of Appeals for the Fifth Circuit, to a new seat created by 92 Stat.

In 2002, at the request of Chief Justice William Rehnquist, she became the first woman to chair the executive committee of the Judicial Conference of the United States.

[2] In 2007, King received the Edward J. Devitt Distinguished Service to Justice Award from the American Judicature Society.

[9] On December 18, 2019, King dissented when the Fifth Circuit declared the Affordable Care Act's individual mandate unconstitutional.