Oswald Herbert Ernst Oswald Herbert Ernst ( June 27 , 1842 – March 21 , 1926 ) was an astronomer , engineer , military educator , and career officer in the United States Army who became superintendent of the United States Military Academy . Over a forty year career , Ernst served as an engineer during Sherman ' s Siege of Atlanta during the American Civil War , commanded U . S . troops at Coamo during the Spanish - American War , Cuba and sat on the original commission for the Panama Canal after retirement from active service . Early life . Oswald Ernst was born June 27 , 1842 near Cincinnati , Ohio , the son of Sarah Otis and Andrew H . Ernst . His mother was descended from Richard Warren , who traveled to Plymouth Colony from Southampton , England on the Mayflower . Andrew Ernst was himself the son of a recent immigrant , a burgomaster who had fled Germany during the Napoleonic Wars and afterwards settled in the Ohio River valley . The younger Ernst was an excellent student , admitted to Harvard in 1858 , left that place of learning to accept an appointment from Ohio to the United States Military Academy at West Point , New York in 1860 . Military career . When the American Civil War broke out , plebe Ernst stayed at the academy with the Union - born cadets while most southerners left for the Confederacy . Ernst graduated USMA just before his twenty - second birthday and was immediately billet ed to First Lieutenant , Corps of Engineers . Within the month , Ernst was employed by the Army of the Tennessee as assistant engineer before Atlanta , took part in the Battle of Ezra Church , and was engaged in siege activities before Atlanta ' s surrender . In October , 1864 , Lt . Ernst was back at West Point as assistant professor of engineering , lecturing about what he ' d learned of practical siege engineering in the four months since his graduation . Ernst married Elizabeth Amory Lee in late 1866 , and spent the years immediately after the war working on constructing fortifications on the Pacific coast , and remained so occupied until 1868 . He was promoted to captain in March 1867 , and had command of an engineer company at Willets Point , Queens , from 1868 until 1871 . After detail as " Astronomer of the U . S . Commission to observe in Spain the Solar eclipse of December 22 , 1870 , " from 1871 until 1878 , Ernst was again lecturing USMA cadets about " practical engineering " and commanding the post ' s elite engineer company . While teaching cadets and writing the " Manual of Practical Military Engineering " , Ernst found time to author articles for " Johnson ' s Encyclopedia " and raise his two daughters Helen Amory and Elizabeth Lee . From 1878 until 1889 , Ernst was chief engineer on Osage and Mississippi River projects , and was responsible for the deepening of shipping routes in Galveston Bay . In 1889 , Ernst became military aide - de - camp to President Benjamin Harrison and chief engineer in charge of Washington ' s public buildings and monuments . In 1893 , the Ernst family returned once again to West Point , this time to occupy the superintendent ' s billet . After the explosion of the USS Maine in February , 1898 , Ernst was promoted to brigadier general of volunteers and put in command of the 1st Division of volunteer troops deployed to the Puerto Rican Campaign .