The attack on Pearl Harbor on December 7, 1941 led to the United States’ entry into World War II and Forest Park’s industrial military aid. A year earlier the Secretary of the Navy selected the 80-acre, former Harlem Racetrack and Harlem Golf Course on Roosevelt Road and Desplaines Avenue for production of ordnance materials for the National Defense. The American Can Company was selected for the construction and management of a new Naval Ordnance Plant, which opened only eight months later, with a large reception on October 29, 1942.

In peak production, the plant manufactured 400 torpedoes a month. The total number of people working in the plant swelled to over 6,000 personnel by late 1943 until late 1944.  

In 1945, the plant was converted from a contractor-operated to a Navy-operated activity but continued to produce torpedoes and related items. In 1970, the Defense Department decided to close the Forest Park plant.  

During the nearly 30 years of service to the Department of the Navy and Department of Defense, the Naval Ordnance Station in Forest Park produced approximately 19,000 torpedoes and overhauled, converted and or modernized several thousands of torpedoes and other items of ordnance material.