Who was Secretary of War when the department was renamed in 1947?
Executive summary
The War Department was statutorily abolished and reorganized by the National Security Act of 1947, effective September 18, 1947, and at that moment the incumbent Secretary of War was Kenneth C. Royall, who served from July 1947 until the office was abolished in September 1947 [1] [2]. Earlier in 1947 Robert P. Patterson had led the department through much of the immediate post‑World War II transition but left office in July, handing the brief final stewardship to Royall [1] [3].
1. The legal pivot: National Security Act and the formal renaming
Congress rewired the U.S. military bureaucracy with the National Security Act of 1947, which converted the War Department into the Department of the Army, created the United States Air Force as an independent department, and established the National Military Establishment under a new Secretary of Defense; the act took legal effect with the abolition of the Secretary of War’s office on September 18, 1947 [4] [2]. Contemporary records and later departmental histories treat that date as the formal handover from the old War Department structure to the post‑war, unified national military organization, and later amendments renamed the National Military Establishment the Department of Defense in 1949 [3] [5].
2. Who held the title in the final days of the War Department
Kenneth C. Royall was the Secretary of War at the time the office was abolished on September 18, 1947; official archival summaries list Royall as Secretary from July 1947 until the September 1947 termination of the office, making him the last person to hold the title Secretary of War [1] [2]. Robert P. Patterson preceded Royall as Secretary of War, serving from September 1945 until July 1947, and is frequently cited for having presented reorganization plans and testimony during congressional hearings on the National Security Act earlier in 1947 [1] [3].
3. Why some accounts foreground Patterson rather than Royall
Reporting and historical narratives sometimes emphasize Robert P. Patterson because he chaired major hearings, submitted organizational charts to Congress, and was a visible architect of postwar procurement and demobilization policy during the legislative debate over reorganization; those actions give Patterson an outsized presence in the record despite Royall holding the office when it was formally abolished [3] [1]. Primary source collections and archival guides reflect this imbalance: Patterson’s testimony and public statements are heavily represented in the War Department records from 1945–47, which can create the impression that Patterson was the final steward even though Royall completed the official tenure [1] [2].
4. How contemporary and later sources name the transition
Encyclopedic and departmental overviews concur that the Secretary of War position ended with the 1947 legislation and that the Department of the Army became the successor organization under the new National Military Establishment; most sources trace the statutory succession to the Secretary of the Army and the newly created Secretary of Defense post [6] [4] [5]. Archival descriptions from the Truman Library and the National Archives explicitly record the dates and officeholders, and they identify Royall as the last Secretary of War while noting Patterson’s prominent role in earlier 1947 policymaking and testimony [1] [2].
5. Competing framings and hidden emphases in modern retellings
Some modern commentary—particularly pieces focused on institutional personalities, reform narratives, or retrospective leadership—tilts toward Patterson because he shaped the policy arguments that produced the 1947 law, whereas sources emphasizing legal formality correctly identify Royall as the final officeholder when the abolition took effect; both framings are defensible depending on whether emphasis is placed on policy authorship or administrative incumbency [3] [1]. Readers should note the agendas implicit in different treatments: policy histories highlight architects like Patterson, archival and legal accounts emphasize dates and incumbency and therefore name Royall as the last Secretary of War [2] [3].
6. Bottom line
Legally and administratively, Kenneth C. Royall was Secretary of War when the department was renamed and the office abolished under the National Security Act effective September 18, 1947; Robert P. Patterson, who served immediately before Royall, remains the more visible figure in many narratives because of his policymaking role during the reorganization debates earlier that year [1] [3] [2].