The Cactus Ordnance Works, on 700 acres in northern Moore County, was begun in the spring of 1942, after the United States government entered into a $5 million contract with the Chemical Construction Company of New York to erect, equip, and staff a plant for the manufacturing of ammonia nitrate, a product of natural gas, to be used in making munitions. Construction was supervised by the United States Army Corps of Engineers, which was given temporary office space at the Moore County Courthouse in Dumas. There the engineers laid out plans for thirty-five staff houses, seven dormitories, seventy-five two-family duplexes, a cafeteria, a canteen, a fire station, and other facilities for an instant industrial town, as well as a railroad spur to the plant. In August 1942 a flag-raising ceremony was held at the COW. By the time of its completion in 1943, recreation clubs had been formed, and a plant newspaper, the COW Puncher (later the Cactuzette) was being printed. Soon the plant had nearly 3,000 employees, enough to prompt Sunray and Dumas to provide shopping and other services.
On May 5, 1943, with the easing of the wartime emergency, Chemical Construction Company officials received orders from Washington to close the COW down. Operations were suspended, and some of the residential structures, mostly trailer houses, were sold as surplus. Later that summer, however, Shell Union and Gas Corporation of San Francisco assumed control of the plant and in early 1944 began manufacturing aviation gasoline. That arrangement lasted until August 1946, when the Emergency Export Corporation took over and reconverted the plant for the purpose of producing ammonia for fertilizers to help bolster grain production in postwar Europe. About 250 tons was manufactured at the COW each day, and 375 people were employed. Emergency Export continued production there until August 15, 1948, when Phillips Chemical, a division of the Phillips Petroleum Company, which had built another plant near the COW in 1943, assumed management.
During the 1950s the COW was one of the nation's largest producers of chemicals for fertilizers. Despite a few cutbacks, employment was stabilized at around 600. By the end of the decade the aged plant was updated and automated. In 1961 a bitter 105-day strike occurred over a contract dispute between Phillips and the Oil, Chemical, and Atomic Workers of America. Due to increasing competition in fertilizer production, the plant's workforce was reduced to around 200 by the late 1960s. In November 1973 the ammonia section, the facility's largest production unit, was shut down. However, nitric acid and ammonium nitrate were still manufactured at the old COW for some time. By the early 1980s the Cactus Ordnance Works had completely shut down.