During the 1936-37 academic year, he also worked as a junior reporter for the New York Daily News.
After the war, Donnelley spent 1946-47 as press attaché at the United States Embassy in Mexico City.
From 1958 to 1961, Donnelley served as Special Assistant to the Under Secretary of State (Christian Herter and later C. Douglas Dillon).
In September of 1966, in response the use of Agent Orange as a defoliant, from Dixon Donnelley, the Assistant Secretary of State for Public Affairs, which read: “Chemical herbicides are being used in Vietnam to clear jungle growth and to reduce the hazards of ambush by Viet Cong forces.
The chemicals are used extensively in most countries by both the Free World and the Communist Bloc for selective control of undesirable vegetation.