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The Twin Cities Army Ammunition Plant created innovations in manufacturing technology and management — and an EPA Superfund site

The Army Ordnance Department authorized construction of the Twin Cities Ordnance Plant (TCOP) in the spring of 1941.

historic photo of workers in ammunition plant
Twin Cities Ordnance Plant workers on the factory line, 1940s. Twin Cities Army Ammunition Plant files, box 143.E.17.2F. Manuscripts Collection, Minnesota Historical Society, St. Paul.
Courtesy of the Minnesota Historical Society

Authorized in 1941, the Twin Cities Army Ammunition Plant (TCAAP) contributed to United States military efforts for more than fifty years. Economic and environmental impacts extended beyond the New Brighton/Arden Hills site into the greater Twin Cities area.

Prior to US entry into World War II, President Franklin D. Roosevelt advocated for the country’s role as the “Great Arsenal of Democracy.” His aid strategy, laid out in the Lend-Lease Act, utilized government-owned, contractor-operated (GOCO) ammunition-manufacturing plants to provide supplies overseas. As a result, the Army Ordnance Department authorized construction of the Twin Cities Ordnance Plant (TCOP) in the spring of 1941. Federal Cartridge Corporation (FCC) of Anoka, a sporting ammunition manufacturer, was contracted to operate the facility.

Land was purchased in rural Ramsey County, about ten minutes north of Minneapolis by car. Crews worked night and day, constructing an operational facility and supporting infrastructure in just six months. The rapid pace continued as ammunition production began, with thousands of Twin Cities workers filling three shifts around the clock. The massive facility eventually functioned like a small city, with its own fire department, security force, hospital, bus system, and rail terminal. Social elements like a plant newspaper, intramural sports leagues, and a choir served to maintain morale.

When Roosevelt visited the plant in September, 1942, he inquired about both the high numbers of women in manufacturing positions and the integration of African Americans into the organization. Indeed, over half the employees were female, known as WOWs (Women Ordnance Workers). And while African Americans in Minnesota were then generally limited to service occupations, men such as Cecil E. Newman and J. W. Pate held supervisory positions at TCOP. FCC President Charles L. Horn also refused to separate employees by race.

Community spirit and innovation marked the World War II era at TCOP. Taxpayers’ committees encouraged high production levels, since workers’ own tax dollars funded the plant. Managers actively sought and implemented employee suggestions that saved time and money. Working under a non-strike agreement, an internal grievance committee of union and non-union members handled labor issues. Horn’s investment in electronics led to the invention of an electric eye to aid assembly machines. Steel-cased cartridges were developed at TCOP to deal with brass shortages.

At war’s end, the plant served as one of five returned-material centers in the US. Employees tested and sorted ammunition for future reserves. Other army ordnance plants sent machinery to be prepared for long-term storage. In 1946, TCOP’s name changed to Twin Cities Arsenal.

The arsenal returned machines to defense manufacturers nationwide when the Korean War developed. This war-and-peace-pattern would be repeated for the remaining life of the plant. When ammunition was needed for the Vietnam War and First Persian Gulf War, production resumed under contracts with FCC. In peacetime, the plant returned to standby status with army oversight. Private companies, including Honeywell and 3M, leased property for defense research and development.

Disputes arose in later generations. Internally, labor strikes stopped work in 1951, 1967, and 1971. Vietnam War protesters targeted the Twin Cities Army Ammunition Plant (TCAAP; renamed in 1963) as a hub of military production in 1971 and 1972. Environmental effects of the manufacturing process and chemical disposal were confronted in the early 1980s

The Environmental Protection Agency (EPA) defined a twenty-five-square-mile “New Brighton/Arden Hills Superfund Site” in 1983. This extended beyond the TCAAP into affected portions of seven nearby communities. A 1987 agreement between the EPA, the US Army, and the Minnesota Pollution Control Agency mandated cleanup of the site at army expense.

The army announced plans to release portions of TCAAP land as excess federal property in 1994. This prompted planning, led by Congressman Bruce Vento, for redevelopment of the area. Several other proposals were drafted and ultimately rejected in subsequent years, until Ramsey County finalized purchase of the land in 2013.

With environmental remediation completed, the City of Arden Hills and Ramsey County partnered with Alatus in 2016 to work toward developing Rice Creek Commons for residential and business use. Other portions of the original TCAAP land are currently utilized as the Rice Creek North Regional Trail and the Arden Hills Army Training Site. The site also hosts public works facilities for Arden Hills, Ramsey County and MnDOT, and the Arden Hills City Hall.

For more information on this topic, check out the original entry on MNopedia.