The son of Walter Benedict Langley and Anna Mae McCaffrey, Harold Langley joined the U.S. Army at the age of eighteen and served from 1943 to 1946, receiving along with his unit the Army Meritorious Service Medal and the Asiatic-Pacific Campaign Medal.
In 1969, the Smithsonian Institution, Washington, D.C., appointed him associate curator of naval history.
While holding that position, he was also an adjunct professor of American history at the Catholic University of America from 1971 to 2001.
Langley's examination of the early practice of naval medicine contains some enlightening and shocking revelations.
Foremost is the ponderous movement of bureaucracies, most notably the Navy Department, which could not produce a decision on the means to provide care and treatment for wounded and infirm sailors.