1980s: Nuclear accidents, such as the meltdowns at Three Mile Island in Pennsylvania in 1979 and at Chernobyl in the Ukraine in 1986, awaken Americans to the dangers of radiation from nuclear energy. Because of these accidents and the build-up of nuclear arms, an international grassroots movement forms to protest the use of nuclear energy. Environmental groups, such as Greenpeace and the Sierra Club, pressure governments to rethink their environmental policies.

Today: In the United States, a moratorium is placed on the building of nuclear energy plants. However, because of its lengthy shelf life, hazardous waste from uranium mining in the southwestern United States continues to be a problem in terms of its handling, transportation, and storage.

1980s: The Cold War, which began as a diplomatic standoff between the United States and the Soviet Union after World War II, reaches its zenith under Ronald Reagan's U...