What was the original name of the Manhattan Project?

The original name of the Manhattan Project was, in fact, the Laboratory for the Development of Substitute Materials. This name reflects the early focus on developing materials that could be used in atomic weaponry, before the scope of the project expanded. The project was initiated during World War II in response to fears that Nazi Germany was developing atomic weapons. The name change to the Manhattan Project was adopted later, reflecting the location of the project's initial offices in Manhattan, New York, and the involvement of various research facilities across the United States. Understanding this name change is essential for grasping the early strategy and organization of the U.S. efforts in atomic research during the war.