In August 1945, the United States unleashed an atomic weapon against the Japanese at Hiroshima and Nagasaki and brought an end to World War II. These bombs killed in two ways -- by the blast's magnitude and resulting firestorm, and by nuclear fallout. After the Soviet Union exploded its first atom bomb in 1949, the Cold War waged between the two superpowers. The arms race resulted in nuclear weapons testing.These tests consisted of above ground and below ground explosions of nuclear devices. The above-ground explosions generated nuclear fallout. This lesson relates to the duties and powers of the president and Congress, to provide for national civil defense in the event of war, as set forth in the Preamble, in Article I, Section 8, Paragraph 18, and in Article II, Section 3, Clause 1 of the Constitution. The lesson uses eight primary source documents dealing with nuclear fallout, six photographs, an artist's rendering of a fallout shelter, and a pamphlet entitled "Facts about Fallout." It correlates to the National History Standards and to the National Standards for Civics and Government. The lesson provides the historical background about the atom bomb (with three resources); and suggests diverse teaching activities for classroom implementation, including pamphlet analysis, compare and contrast, photograph analysis, and student research projects. Appended are a photograph analysis worksheet and the primary source documents. (BT)