This dissertation examines nuclear weapons manufacturing in the American West from 1942 through the early 1990s. Specifically, it examines Hanford Engineer Works in Washington, Pantex in the Texas Panhandle, Rocky Flats Plant in Colorado, uranium mines and mills across the American West, and Los Angeles’s ICBM industry. Using the tools of environmental, business, and nuclear history, this manuscript asserts several related propositions. First, the military-industrial complex was not a top-down organization directed by a scientific-technological elite, but a diffuse system supported by, and comprised of, working Americans who found lucrative paychecks and a distinctive social status by taking jobs in the weapons industry. Second, private firms as much as the federal state, and at times even more so, shepherded the U.S. effort to procure nuclear weapons and delivery systems. Third, the state’s demand for nuclear weapons pushed private firms to manufacture nuclear materiel as quickly as possible and overlook the environmental and human health consequences of rapid nuclear procurement. Fourth, this dedication to procurement over human and environmental health galvanized thousands of westerners to form anti-nuclear movements and seek justice for decades of radioactive contamination. Recognizing that the success of America’s nuclear weapons program, and indeed the success of the military-industrial complex, itself, was contingent on the participation of millions of Americans and dozens of private corporations, this manuscript offers a bottom-up interpretation of the military-industrial complex. This dissertation intervenes in a historiography that privileges the role of the American state in manufacturing nuclear weapons at the expense of private industry, regards the military-industrial complex as a monolithic entity, and has failed to examine how nuclear weapons work produced both economic benefits and physical pains for working Americans. It recognizes that private firms held and exercised agency in producing nuclear weapons. Nuclear weapons work provided westerners with a new source of economic wealth while poisoning western bodies and western landscapes. By showing how nuclear weapons work enriched some westerners and harmed others, this manuscript explains why some Americans continue to fight against the military-industrial complex and why others continue to support it.