Morgan joined the
Naval Historical Center in 1952, when it was the
Naval History Division of the
Office of the Chief of Naval Operations (Op-09B9), Navy Department, serving under the successive Directors of Naval History, Rear Admiral
John B. Heffernan, Rear Admiral
Ernest M. Eller, Vice Admiral
Edwin B. Hooper, Rear Admiral
John D. H. Kane. Initially assigned as a naval officer, Morgan remained there for thirty years, serving as Head, Research Branch, from 1954 to 1982 and appointed additionally as Senior Historian, before he retired in March 1982. In 1952, he became interested in the officers who had served in the Continental Navy and this led to the publication of his doctoral thesis in 1956 and his first book in 1959,
Captains to the Northward. As he was working on this he came into contact with the manuscript collector and historian
William Bell Clark and with Rear Admiral
Ernest M. Eller, played a major role in undertaking the
Naval Documents of the American Revolution project. Beginning about 1956, Morgan was the professional historian and master
documentary editor who implemented the project under Clark's editorship. On Clark's death in 1968, Morgan succeeded him as editor, completing the first nine volumes by the time of his retirement in 1982. He died at
Silver Spring, Maryland. ==Awards==