In a surprisingly low-key and carefully worded statement, President
Harry S. Truman (above) informed the American people that the
Soviets exploded a nuclear bomb. The Soviet accomplishment,
years ahead of what was thought possible by most U.S. officials,
caused a panic in the American government. 

The United States developed the atomic bomb during the latter
stages of World War II and dropped two bombs on Japan in August
1945.