Dennis Hart Mahan

Military theorist, born in New York City, New York, USA, the father of Alfred Thayer Mahan. He trained at West Point (1824), then went to France to study in an army school, and returned to West Point (1832) where he spent the rest of his career as a professor of civil and military engineering. He was known for his books on fortifications and other aspects of military engineering, but it was his theories, particularly his stress on mobility, boldness, and speed, that heavily influenced senior commanders in both the Mexican War and Civil War.

Dennis Hart Mahan (April 2, 1802 – September 16, 1871) was a noted American military theorist and professor at the United States Military Academy at West Point.

A native of New York City, Mahan graduated from West Point in 1824. In 1830 he was promoted to professor of civil and military engineering. As a teacher of military science, Mahan promoted defensive tactics on the battlefield. His influence was particularly felt during the Siege of Petersburg, where his theories affected the lives of the nearly 200,000 men in the trenches around Petersburg and Richmond.