He returned to West Point as an instructor from 1921 to 1923. He next attended a series of schools, beginning with the U.S. Army Infantry School from 1923 to 1924, then the Command and General Staff School from 1924 to 1925, and finally going back overseas to attend the French École supérieure de guerre from 1925 to 1927. He returned to the United States as assistant executive in the office of Assistant Secretary of War from 1928 to 1931, followed by the Army War College from 1931 to 1932, and an assignment as an instructor at the Command and General Staff School from 1932 to 1936.
Prior to World War II he held a series of staff assignments, including time in the Budget and Legislative Planning Branch of the War Department General Staff from 1938 to 1941, and Assistant Chief-of-Staff for personnel.
In World War II he served very briefly as assistant division commander (ADC) of the 4th Infantry Division. He organized the 85th Infantry Division and served as commander from April 1942 to February 1943 until he was succeeded by Brigadier General John B. Coulter, his ADC. He next took command of XV Corps and served with it through Normandy, France, Rhineland, and Central Europe campaigns. He became commander of Seventh United States Army, and was in that billet when World War II ended in August 1945.
Following the war he was on the Secretary of War's Personnel Board from September 1945 to April 1946, and a senior member of the Chief-of-Staff's Advisory Group from 1946 to 1948. Prior to his selection in 1949 as Vice Chief of Staff he was Deputy Chief-of-Staff for administration, 1948–49. He retired in 1951.
Haislip is responsible for introducing Dwight D. Eisenhower to Mamie Doud. Eisenhower was a second lieutenant and Haislip a first lieutenant at Fort Sam Houston at the time. At Eisenhower's funeral, he served as a pall-bearer.[3]
Major assignments
Assistant Chief-of-Staff for personnel – February 9, 1941 to January 19, 1942
Assistant Division Commander, 4th Motorized Division – January 20, 1942 to March 9, 1942
After retiring from active duty in 1951, Haislip went on to become Governor of the Soldier's Home in Washington, D.C., a position he filled from 1951 to 1966.
Haislip died on December 23, 1971, at Walter Reed Army Medical Center after suffering a stroke, and was buried in Arlington National Cemetery.[4] His wife, the former Alice Jennings Shepherd (1897–1987), whom he had married on July 14, 1932, was later buried beside him.
Taaffe, Stephen R. (2013). Marshall and His Generals: U.S. Army Commanders in World War II. Lawrence, Kansas: University Press of Kansas. ISBN978-0-7006-1942-9. OCLC840162019.