Archibald Stevens Alexander (October 28, 1906 – September 4, 1979) was an American lawyer, civil servant, and Democratic politician.

[3] Through his mother, he was a grandson of Lily (née Whitney) Barney (sister of William Collins Whitney) and Charles T. Barney, the former president of the Knickerbocker Trust Company,[4] and great-grandson of Ashbel H. Barney, president of Wells Fargo & Company and Brig.-Gen. James Scollay Whitney, president of the Metropolitan Steamship Company.

After completing law school Alexander joined the New York firm of Carter, Ledyard & Milburn, where he was a partner from 1940 to 1949.

[6] In 1947 Alexander was appointed to the State Department's Foreign Service Selection Board and served as a consultant to the Atomic Energy Commission on security and personnel matters.

In 1963 he was appointed assistant director of the Arms Control and Disarmament Agency, remaining in this position until 1969.

Together, Susan and Archibald were the parents of: After her death in 1935, he married Jean Struthers Sears (1907–1983) at Beverly, Massachusetts, on August 4, 1937; her sister was Emily Sears, who married Henry Cabot Lodge Jr.[9] Alexander died on September 4, 1979, at his home in Bernardsville, New Jersey, after a short illness.