West Point in the Making of America






Portrait, Dennis Hart Mahan

Portrait, Dennis Hart Mahan

Related Items


Mahan’s civil engineering textbook

Fortification treatise

Fortification treatise

Artillery treatise

Artillery treatise

Sylvanus Thayer (1785–1872)

As an undergraduate at West Point, Mahan taught mathematics to underclassmen. Graduating at the top of his class, he soon returned to the Academy, remaining on the faculty for more than forty years.

Teaching mathematics, and later a professor of engineering, Mahan redesigned the Academy’s engineering programs. His textbooks became American standards of engineering instruction.

Mahan also taught the course on military science taken by virtually every West Pointer who fought in the Civil War. Despite its odd title, his textbook, Elementary Treatise on Advance-Guard, Out-Post, and Detachment Service of Troops (1847, often reprinted), was America’s first comprehensive work on tactics and strategy.

Professor and Mrs. Mahan, the former Mary Helena Okill, raised five children. Their oldest son, Alfred Thayer, chose the U.S. Naval Academy and became a renowned naval strategist and historian. A younger son, Frederick August, graduated from West Point in 1867.


West Point after the Civil War

Key Figures

Sylvanus Thayer
Sylvanus Thayer
Class of 1808

Dennis Hart Mahan
Dennis Hart Mahan
Class of 1824

Smithsonian National Museum of American History

E-mail Signup | Sponsors | Credits
West Point in History Introduction 1802–1860 1861–1870 1866–1914 1914–1918 Epilogue Introduction 1802–1860 1861–1870 1866–1914 1914–1918 Epilogue A School for the Nation West Point after the Civil War