Washington DC: United States Department of the Interior, National Park Service, 1956. Revised Edition. Wraps. [4], 46, [2] pages. Occasional footnotes. Illustrations. Bibliography. Appendix I and II. Decorative cover. Cover has some wear and soiling. Signature of H. Langley on title page (acquired as part of Langley's impressive library from his estate). Harold David Langley (15 February 1925 – 29 July 2020) was an American diplomatic and naval historian who served as associate curator of naval history at the Smithsonian Institution from 1969 to 1996. As a naval historian, he was a pioneer in exploring American naval social and medical history. Langley began his professional career at the Library of Congress, Manuscripts Division, in Washington, D.C., where he served as a manuscripts assistant in 1951-52, while a graduate student. Moving to the University of Pennsylvania Libraries in Philadelphia, Pennsylvania, where he was a graduate student, he served as a manuscripts specialist, rare book collection, 1952-54. Returning to the Library of Congress, he was a manuscripts specialist, there in 1954-55. In 1955, Marywood College in Scranton, appointed him assistant professor of history. He remained there until 1957, when he received an appointment as a diplomatic historian in the U.S. Department of State. In 1964, Catholic University of America appointed him associate professor, and in 1968 promoted him to full professor in 1968. In 1969, the Smithsonian Institution, appointed him associate curator of naval history. While holding that position, he was an adjunct professor of American history at the Catholic University of America from 1971 to 2001. More