He was the second of three senior State Department officials—the first being William Hunter and the third Wilbur J. Carr—whose overlapping careers provided continuity and good management in American foreign policy for over a century, from the administration of President Andrew Jackson until that of Franklin D. Roosevelt.

Adee was again in effective charge of the State Department during the Boxer Rebellion in August and September, 1900,[1] because Hay was ill and the Assistant Secretary David Jayne Hill was away from Washington.

[citation needed] He is buried at Oak Hill Cemetery in Washington, D.C.[2] Adee never married and fathered no children.

Adee is said to be a major influence on characterization of Nero Wolfe by Rex Stout according to the latter's official biographer John J. McAleer.

Adee being a scholar, sleuth, gourmet, bachelor, a model of efficiency, a master of the English language is said to have inspired the characterization of Wolfe.