Harold B. Simpson, Air Force officer and historian, son of Harry Leon and Louise (Brown) Simpson, was born in Hindsboro, Illinois, on April 3, 1917. He graduated from the University of Illinois (B.S., 1940; M.S., 1950) and Texas Christian University (Ph.D., 1969). Despite a degree in accounting, he was commissioned a second lieutenant in the United States Army Cavalry when he graduated in 1940 but was transferred to the Air Force (then known as the Army Air Corps) in 1941. During World War II he served in the Southwest Pacific for thirty-three months with the 374th Troop Carrier Group and was decorated with a Presidential Unit Citation (with two Oak Leaf Clusters), the Air Force Commendation Medal, and the Southwest Pacific Campaign Medal (with three Battle Stars).
After the war he stayed in the Air Force and rose to the rank of colonel in 1954, graduating from the Air Tactical School, the Air Command and Staff College, the Armed Forces Staff College, and the Air War College. In 1959 he was assigned to be Comptroller of the Twelfth Air Force in Waco, Texas, and served in that position until his retirement in 1963 after twenty-three years of service.
All of his life Simpson had a strong interest in the Civil War with special interest in Confederate military leadership, especially John Bell Hood. By the early 1950s he was publishing short papers, and he began collecting volumes on Confederate history. After his discharge from the Air Force in 1963, he joined the history faculty at Hill Junior College (now Hill College), Hillsboro, Texas. He was still in uniform when he lectured his first classes, and the students called him "the Colonel," which became their name for him for the remainder of his career.
His dissertation at Texas Christian University was The History of Hood's Texas Brigade, 1861–1865, after which he completed a four-volume history of Hood's Brigade. After its publication he became known as the authority on this unit. Subsequently he authored, edited, or contributed to twenty-six volumes, including Gaines' Mill to Appomattox (1963), Cry Comanche: Second U.S. Cavalry in Texas, 1855–1861 (1979), Brawling Brass: North and South (1960), and Audie Murphy, American Soldier (1975). In addition, he founded the Hill College Press in 1964 and was editor for the many books published during his life.
Simpson reactivated the Hood's Texas Brigade Association and was active in the Sons of Confederate Veterans and the Civil War Round Tables of Waco and Fort Worth. He was a fellow of the Texas State Historical Association and the Company of Military Historians, and he received numerous awards for his publications and his efforts on behalf of preserving Civil War history. In 1979 he began the Confederate History Symposium at Hill College, an event which drew capacity crowds annually. His personal library became the nucleus for the Texas Heritage Museum in 1963, and he began collecting material for what became the Texas Heritage Museum, both now part of the Harold B. Simpson History Center at Hill College.
On March 1, 1941, Simpson married Lorraine Hennings; they had five children. On September 5, 1977, he married Vera DeLandri. The Colonel continued to lecture his classes at Hill College after being diagnosed with terminal cancer, surviving by force of will until after final exams that semester. He died at Hill Regional Hospital on May 31, 1989.