professor, he served in the engineer troops from September 6, 1854, to June 27, 1857, was promoted to first lieutenant on December 1, 1856. From June 27, 1857, to August 31, 1859, Casey was principal assistant professor of engineering, and he was in command of a detachment of engineer troops in Washington Territory, from November 21, 1859, to April 1861. During the American Civil War he was stationed at Fort Monroe as an assistant engineer on the staff of the general in command of the Department of Virginia, from June 11 to August 15, 1861, being promoted to captain on August 6. Casey was then superintending engineer of coastal fortifications in Maine and involved in recruiting engineers for the duration of the war, until July 25, 1866. Casey became a major on October 2, 1863, and was made a brevet lieutenant colonel and colonel on March 13, 1865. During the war, he served with the North Atlantic Squadron during the First Expedition to Fort Fisher from December 8 to 29, 1864. The following year he was on the special board of engineers for work on Willet's Point from April 7 to June 20, and for work on Fort Preble, Fort Scammel, Fort Popham and Fort Knox on the Penobscot River from August 1865 to February 1866. After a leave of absence ending February 25, 1867, Casey served as superintending engineer on the construction of Forts Preble and Scammel from March 1 to November 18, 1867. He was then made assistant to the Chief of Engineers on November 18, 1867, moving to Washington, D.C., where Casey would live most of the rest of his life. He went on inspection tours from April to October 1868, and left the position January 2, 1879. In 1873 Casey was invested as an Officer of the French Legion of Honor in recognition of his work as an engineer. Casey headed the division the Office of the Chief of Engineers responsible for military engineers, equipment, and fortifications. From March 3, 1877, to April 1, 1881, Casey headed the Office of Public Buildings and Grounds, District of Columbia, overseeing construction of the Potomac aqueduct (March 3, 1877 to August 12, 1882), the last two-thirds of the State, War, and Navy Building (March 3, 1877 to May 31, 1888), and the completion of the Washington Monument (June 25, 1878, to April 4, 1888). The Washington Monument Casey's most