A Civil War Biography

Dennis Hart Mahan

Mahan was born 2 April 1802 in New York City. He grew up in Norfolk, Virginia, and received an appointment to the United States Military Academy at West Point from his adopted state. He graduated at the top of the class of 1824. During his third year at the academy he had been appointed acting assistant professor of mathematics and continued in that capacity after being commissioned a 2nd lieutenant in the corps of engineers. In 1825 he was assigned as principal assistant professor of engineering at his alma mater. In 1826 the war department sent Mahan abroad to study public engineering works and military institutions. He spent some time at the military school of application for engineers and artillerists in Metz, France, then considered the foremost school of military studies in the world. Mahan returned to West Point in 1830 and took up duties as the acting professor of engineering. He accepted the chair permanently in 1832, relinquishing his commission in the corps of engineers. In 1838 the duties of dean were added. He would maintain these two position for the remainder of his life. Mahan was a member of many scientific societies in the United States and one of the corporate members of the National academy of sciences in 1863.

The many text books he wrote gained him a world-wide reputation. His texts were used at the academy and in many universities around the world. His text on field fortifications, "Treatise on Field Fortifications, Containing Instructions on the Methods of Laying Out, Constructing, Defending and Attacking Entrenchments, With the General Outlines Also of The Arrangement, the Attack and Defense of Permanent Fortifications", first published in 1836 and used until well after the Civil War, was considered the bible of field fortifications. Mahan died near Stoney Point, New York on 16 September 1871, taking his own life being distraught when he learned he was recommended to be retired.

His son was the famous naval historian Alfred Thayer Mahan. Alfred was born on 27 September 1840 at West Point. He graduated from the Naval Academy at Annapolis in 1859 and spent over 40 years in the navy retiring with the rank of rear admiral. Alfred is best known for his many books on sea power and how it influenced history.

There were two other sons, Frederick Augustus Mahan and Dennis Hart Mahan, born in 1847 and 1849 respectively. Frederick followed in his father's footsteps, graduating from West Point in 1867 and was assigned to the corps of engineers. Frederick would rise to the rank of captain and spend his career as an engineer and an instructor at West Point. He edited much of his father's later work. Dennis Hart Mahan graduated from the Naval Academy in 1869. The younger Dennis would rise to the rank of commodore and is best known for serving in the Philippine Insurrection, commanding the USS Indiana and returning to active duty to command the forces at Honolulu, Hawaii during World War I.

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