The Southwestern Division, U.S. Army Corps of Engineers, was created in 1937, as a result of large and catastrophic flood events that led up to Congress passing the Flood Control Act of 1936. That Act recognized that flood control was a federal responsibility and authorized 211 flood control projects in 31 states. It authorized five reservoirs and a variety of levee construction and improvement projects on the Arkansas River Drainage Basin. To oversee these projects, the U.S. Army Corps of Engineers established two offices on July 1, 1937: the Little Rock District and the Southwestern Division. SWD also took over areas in the watershed of the Canadian River and its tributaries west of the Texas-New Mexico border.
In 1939, SWD’s workload increased with the addition of two new Districts: the Denison District (sponsored by House Majority Leader Sam Rayburn to build Texoma Reservoir on the Red River in Texas for both flood control and hydropower) and the Tulsa District (for flood control, hydropower, and navigation).
Nearly doubling SWD’s territorial area was the addition of the Galveston District on Jan. 15, 1941. With the addition of the Galveston District, the geography and the topography of SWD ranged from wetlands on the eastern portion to desert on the west. Galveston District was transferred to SWD due organizational changes in the Corps brought on by new military requirements for World War II. For that same reason, SWD moved from Little Rock to Dallas on Feb 1, 1941, ensuring a more centralized and accessible location from which to oversee the Districts.
Post World War II, renewed economic growth in America led to the creation of SWD’s Fort Worth District in March 1950. This development was a result of the increased construction of reservoirs in north Texas on the Brazos and Trinity Rivers. A sub-office in Fort Worth faced closure because of budgetary constraints, but local officials, including the Trinity Improvement Association, fought for a District Office in Fort Worth. A major flood event on the Clear Fork of the Trinity River added urgency to the cause, and the Fort Worth District was created.
The Middle East District and the newly formed Expeditionary District—came under the authority of the U.S. Army Corps of Engineers Southwestern Division after a Transfer of Authority ceremony of August 5, 2025, from the Transatlantic Division, that was created to provide unified command of all USACE operations within the U.S. Central Command area of responsibility.
Prior to its the Transatlantic Division's activation, three major USACE organizations supported that theater: the Gulf Region Division in Baghdad, the Afghanistan Engineer District in Kabul, and the Transatlantic Programs Center in Winchester.
Upon activation, the Gulf Region Division was disestablished, and its remaining districts—Gulf Region District (Baghdad) and Gulf Region South District (Tallil)—were reassigned to the new Division. It also assumed oversight of the Afghanistan Engineer District-North (Kabul), the newly created Afghanistan Engineer District-South (Kandahar), and the Middle East District, renamed from the Transatlantic Programs Center.
(Source: The Southwestern Division, 50 Years of Service, by D. Clayton Brown, PhD)