Thayer, Sylvanus, 1785–1872, American soldier and educator, b. Braintree, Mass., grad. Dartmouth, 1807, and West Point, 1808. During the War of 1812 he served as an engineer, and afterward he was sent to Europe to study military schools and fortifications. From 1817 to 1833 he served as superintendent at West Point, which he so thoroughly reorganized, placing it on a sound basis, that he is known as the "father of the Military Academy." He endowed an academy at Braintree and established and endowed (1867) the Thayer School of Civil Engineering at Dartmouth.