1938: German scientists split the first uranium atom.
1939: Albert Einstein writes a letter to Roosevelt about a potential bomb using uranium.
World War II starts (September 3, 1939).
1941: Roosevelt decides to build the atomic bomb (October 9, 1941).
Manhattan Project starts (December 6, 1941).
Attack on Pearl Harbor...United States enters WWII (December 7, 1941).
1942: Los Alamos, New Mexico chosen as site for atomic bomb facility (November 16, 1942).
1945: Roosevelt dies and Harry S. Truman becomes the next president (April 12, 1945).
Germany surrenders (May 8, 1945).
Atomic bomb successfully tested - Trinity Test (July 16, 1945).
Potsdam Conference starts (July 17, 1945).
President Truman decides to drop the atomic bombs (July 21, 1945).
Japan warned to surrender (July 26, 1945).
Japan declines to surrender (July 28, 1945).
Potsdam Conference ends (August 2, 1945).
Hiroshima is bombed (August 6, 1945).
Soviets pledged enter the war on August 15, 1945.
Nagasaki is bombed (August 9, 1945).
Japan surrenders and World War II ends (August 14, 1945).
Japan signs surrender documents (September 2, 1945).
1939: Albert Einstein writes a letter to Roosevelt about a potential bomb using uranium.
World War II starts (September 3, 1939).
1941: Roosevelt decides to build the atomic bomb (October 9, 1941).
Manhattan Project starts (December 6, 1941).
Attack on Pearl Harbor...United States enters WWII (December 7, 1941).
1942: Los Alamos, New Mexico chosen as site for atomic bomb facility (November 16, 1942).
1945: Roosevelt dies and Harry S. Truman becomes the next president (April 12, 1945).
Germany surrenders (May 8, 1945).
Atomic bomb successfully tested - Trinity Test (July 16, 1945).
Potsdam Conference starts (July 17, 1945).
President Truman decides to drop the atomic bombs (July 21, 1945).
Japan warned to surrender (July 26, 1945).
Japan declines to surrender (July 28, 1945).
Potsdam Conference ends (August 2, 1945).
Hiroshima is bombed (August 6, 1945).
Soviets pledged enter the war on August 15, 1945.
Nagasaki is bombed (August 9, 1945).
Japan surrenders and World War II ends (August 14, 1945).
Japan signs surrender documents (September 2, 1945).