The United States ended the war in the Pacific by dropping atomic bombs on Hiroshima and Nagasaki, Japan, in August 1945, killing more than 100,000 Japanese civilians and demonstrating the devastating power of these new weapons. Neither Congress nor the public understood the terrifying capabilities of atomic weapons prior to August 1945, as development of the bomb had been shrouded in secrecy. Shortly thereafter, Congress debated how to meet the unprecedented political, social, and economic issues precipitated by the revolutionary development of the atomic bomb and nuclear technology.

Atomic power must be controlled to prevent a push-button war.

Representative Helen Gahagan Douglas of California, Press Release, 1945