Manhattan Project

The Manhattan Project was the project to develop the first nuclear weapon during World War II. Formally designated as the Manhattan Engineer District , it refers specifically to the period of the project from 1942-1946. The project's roots lay in scientists' fears since the 1930s that Nazi Germany was also investigating nuclear weapons of its own. Born out of a small research program in 1939, the Manhattan Project eventually employed more than 130,000 people and cost nearly $2 billion.