1942-1953 By akgreen 1852 U.S. Nuclear Submarine 1942 Manhattan Project 1942 1st Atomic Bomb Agreement Signed 1943 Jefferson Memorial 1944 The G.I. Bill of Rights 1945 Franklin D. Roosevelt becomes President 1945 Yalta Conference 1945 Bombing of Hiroshima and Nagasaki 1945 United States enters the United Nations 1947 Creation of the Central Intelligence Agency, the Department of Defense, the Joint Chiefs of Staff, and the National Security Council 1948 Marshall Plan 1950 Development of Hydrogen Bomb 1951 Twenty-second Amendment 1953 Nuclear Test 1953 Dwight D. Eisenhower became President