1941 – He received a congressional appointment to the United States Military Academy.

1942 – In August, he flew with the 93d Bombardment Group to England, the first B-24 Group to join the Eighth Air Force.

1944 – He served in various positions with the group, including commander of the 329th Bombardment Squadron, group operations and then executive officer.

1944-1945 – Brown was appointed assistant operations officer, 2d Air Division, in May. He assumed similar duties in May with Headquarters Air Training Command at Fort Worth, Texas.

1946 – He joined Headquarters Air Defense Command at Mitchel Field, N.Y., as assistant to Air Chief of Staff, Operations, and later became assistant deputy for operations.

1950 – He became commander of the 62d Troop Carrier Group at McChord Air Force Base, Washington, which operated between the West Coast and Japan.

1952 – He commanded the 56th Fighter Wing at Selfridge Air Force Base, Michigan, and in May joined Fifth Air Force Headquarters at Seoul, Korea, as director for operations.

1953 – In July, Brown assumed command of the 3525th Pilot Training Wing at Williams Air Force Base, Arizona.

1956 – He entered the National War College, and after graduation, served as executive to the Chief of Staff, U.S. Air Force.

1959 – In June, he was selected to be military assistant to the Deputy Secretary of Defense, and later was military assistant to the Secretary of Defense.

1963 – Brown became commander of the Eastern Transport Air Force, McGuire Air Force Base, N.J. in August.

1964 – In September, he was selected to Joint Task Force II, a Joint Chiefs of Staff unit formed at Sandia Base, New Mexico to test weapon systems of all the military services.

1966-1968 – He served as the assistant to the chairman, Joint Chiefs of Staff, in Washington, D.C.

1970 – In September, General Brown assumed duty as commander, Air Force Systems Command, with headquarters at Andrews Air Force Base, Maryland.

1973 – Brown was appointed by President Richard Nixon to be Chief of Staff of the United States Air Force.

1974 – He became Chairman of the Joint Chiefs of Staff, Department of Defense.

1978 – General Brown retired on the 21st of June  and died on the 5th of December.