"atomic bomb test" britannica.com
The Manhattan Project was first proposed by the vice president, Harry S. Truman and requested by the scientists Albert Einstein, Leo Szilard, and Robert Oppenheimer in December 28, 1942. Before this time, Germany had been working on making the atomic bomb. The Manhattan Project was what caused the Cold War and the atomic era. The Manhattan Project became the entrance of the atomic era making technologies using nuclear power.