was chief engineer at the Siege of Corinth. For the rest of the Civil War, Cullum inspected or built defenses at: Cairo, Illinois; Bird's Point, Missouri; Fort Holt, Kentucky; Columbus, Kentucky; Island Number Ten; New Madrid, Missouri; Corinth, Mississippi; Harpers Ferry, West Virginia; Winchester, Virginia; Martinsburg, West Virginia; Boston Harbor; Nashville, Tennessee; the Potomac aqueduct; Baltimore; and Washington, D.C. He served on boards concerning Timby's Revolving Iron Tower, proposed military bridges, and Army Corps of Engineers officers being considered for promotion. In 1862, Cullum was appointed Chief Engineer of Halleck's armies in the Department of the Missouri. He was Superintendent of West Point from 1864 to 1866. On 8 March 1866, President Andrew Johnson nominated Cullum to be appointed to the grade of brevet major general, USA, to rank from 13 March 1865. He was mustered out of the volunteers on 1 September 1866. In 1867, Cullum published the first edition of his Biographical Register of the Officers and Graduates of the United States Military Academy, covering all graduates from the founding of West Point to the class of 1840. The New York Times wrote that "We know of no single contribution to the military history of the Nation so rich in invaluable data and so essential to the future historian or student of American history." Later life and death Cullum retired from active service 13 January 1874, with the permanent rank of colonel and the brevet rank of major general, and returned to New York City. Following his retirement, he married Elizabeth Hamilton, sister of Major General Schuyler Hamilton and the wealthy widow of Major General Henry W. Halleck. Cullum was vice-president of the American Geographical Society, president of the Geographical Library Society of New York and a member of the board of managers of the Association for Improving the Condition of the Poor. He was also a member of the Farragut Monument Association, a delegate to the 1881 conferences of the Association for the Reform and Codification of the Law of Nations and of the International Geographical Conference, a corresponding member of the Massachusetts Historical Society, and a member of the American Historical Society and the American Academy. Cullum died on 28 February 1892 in New York City, of pneumonia. He is interred at Green-Wood Cemetery in Brooklyn. Cullum left part of his fortune for the continuance of his Biographical Register and for an award of the American