In 1960, Francis Gary Powers' U-2 spy plane was shot down over the Soviet Union. The plane had provided a high-tech peek behind the Iron Curtain during the Cold War.
Ten years after American troops arrived in South Vietnam, communists seized Saigon in an attack that brought the war to a startling conclusion.
The international race to develop biological weapons during the 20th century.
In the Philippines, Army Rangers liberated 513 prisoners of war three years after the Bataan Death March.
A revealing portrait of one of America's most paradoxical leaders.
Though first seen only as an expensive luxury, Alexander Graham Bell's telephone soon transformed American life and became a necessity.
Equipment failure, human error and bad luck led to the country's worst nuclear accident in 1979.
Major Walter Reed's discovery in 1900 that mosquitoes spread yellow fever halted an outbreak and led to the disease's eventual eradication.
Joseph Goebbels, the second most powerful man in Nazi Germany, was the mastermind behind Adolf Hitler's success.