He graduated from the University of Wisconsin, and worked for Chase Bank in Panama before joining the State Department in 1940.

[1][2] Adair was posted to various economic positions in US missions around Europe, particularly the American Embassy in Paris, France.

[1] Adair also served as Deputy Chief of Mission in Buenos Aires in 1963 until his appointment as Ambassador.

He was appointed Ambassador Extraordinary and Plenipotentiary of the United States to Panama on 6 May 1965, presenting his credentials to President Marco Aurelio Robles Méndez on 13 May 1965.

In 1966, Panamanian student demonstrators struck Adair in the back with a milk carton filled with red paint.