During World War II, Ronan served in U.S. Army Air Forces communications in the China Burma India Theater from 1942 to 1945.

Ronan was appointed acting ward committeeman in 1959, elected in 1960, and reelected in 1964; he served as member of the Chicago Planning Commission from 1959 to 1964.

Ronan was elected as a Democrat to the 89th, 90th, and 91st Congresses, and served the sixth district from January 3, 1965, until his death at age 55 in 1969.

Ronan's successor, George W. Collins, served only until December 1972, killed in the crash of United Airlines Flight 553 in Chicago.

This article incorporates public domain material from the Biographical Directory of the United States Congress