The events covered include the geopolitical events of the era--from World War II (1939-1945) and the Holocaust to the formation of the United Nations and the start of the Cold War in 1945, from the Korean War (1950-1953) to the war in Vietnam (1959-1975). Essays also address important social and cultural developments in literature, the arts, music, law, and social and civil rights legislation. Among the many broad subjects receiving extensive coverage are the emerging environmental movement and the growing awareness of pollution; Europe's changing political divisions and shifting alliances; global human rights struggles, including those of women, children, minority groups, and political refugees; the nuclear age; space exploration; postcolonial struggles and revolutionary political movements; dictatorships; and famine and natural disasters. This set also covers major advances in medicine, science, and technology, including those discoveries that brought fundamental changes to daily life beginning in the early 1940's. Medical scientists learned that DNA carries hereditary information and that its structure is in the form of a double-helix; they developed the polio vaccine and determined the structure of insulin and penicillin; and they advanced x-ray photography for medical purposes. Milestones were reached in computer technology, aviation, physics, astronomy, geology, and telecommunications.