It began with the Manhattan Project, a joint military, industrial, scientific, and academic effort to determine the feasibility of an atomic bomb and the means to build one. At the same time that the Manhattan Project was going forward, in the utmost secrecy within the United States but under the watchful eyes of Stalin’s spies, the United States Navy was exploring the use of the atom as a power source for ships and submarines. Scientists and researchers in Germany, the Soviet Union, and the United Kingdom were looking into the atom as a weapon, but efforts everywhere were dwarfed by that underway in the United States.
When the Second World War ended, only the United States had the possession of the atomic bomb, and the accumulated knowledge to build one. Bigger and more powerful atomic weapons were already in development, at the same time studies of how to miniaturize the atomic bomb were underway, in order for it to be used in naval torpedoes, heavy artillery, and possibly even as a hand-held infantry weapon, launched from a bazooka like device. Delivery of atomic weapons by various means soon took a back seat to a yet more powerful device, the thermonuclear hydrogen bomb, which rendered the bomb design used on Hiroshima and Nagasaki obsolete.
Here is a list of events of the history of America’s nuclear weapons program.
1. The atom was all the rage in the late 1940s and 1950s
Following the atomic bombings of Hiroshima and Nagasaki, in which two bombs of an entirely different design were used, the branches of the United States military all sought the means to employ atomic weapons to support their missions. The US Army explored the use of atomic weapons in the shells for howitzers, in tanks, and in hand operated infantry weapons similar to mortars. The Air Force demanded control of the atomic weapon inventory, and postulated that atomic bombs dropped by Air Force bombers rendered the United States Navy obsolete, and thus redundant. The Navy began studies of launching atomic weapons from submarines operated using atomic power. Accordingly numerous new designs for warheads, which nearly all operated using the implosion of plutonium were developed.
Plutonium is created by breeder reactors, and the creation of plutonium was one of the major goals of the Manhattan Project. Both the Trinity Test bomb and the weapon dropped on Nagasaki were plutonium implosion weapons, by contrast the bomb dropped on Hiroshima had been of a design known as a uranium gun. The creation of several different delivery systems for nuclear weapons was one reason for the extensive nuclear testing in the atmosphere during the 1950s, newly designed weapons needed to be tested for their energy release, nuclear yield, and feasibility as a usable weapon. American atomic and nuclear testing in the atmosphere occurred until the early 1960s, in the Pacific and in the Nevada desert, until the Partial Test Ban Treaty took effect during the administration of President Kennedy.