[[Image:Fat-Man.jpg|right|thumb|A replica of the ''Fat Man''.|300px]]
The '''Manhattan Project''' (''Russ: Project ENORMOZ''<ref>[https://studentshare.org/history/1522806-cold-war-essay#: Soviet Intelligence Operation in America during the Cold War - Assignment Example]</ref>) was a 6-year effort to develop a nuclear [[fission]] weapon before the [[Nazi]]s could, sparked by a warning from European scientists to US [[President Roosevelt]].
* The Manhattan Project had its roots in a single letter sent from a group of Hungarian scientists to President Franklin Delano Roosevelt with the help of world-renowned physicist [[Albert Einstein]]. This letter outlines what they saw as a very real and very pressing problem confronting the U.S. and the world—that Hitler and Germany might develop a weapon based on nuclear fission. This letter led to the development of a small research team to begin a United States effort to build the bomb first ... [https://www.cbsnews.com/8301-505125_162-30940115/lessons-from-the-manhattan-project/?tag=bnetdomain]