With over a million already dead, heroic American soldiers and nurses served in the closing battles of World War I.
The international race to develop biological weapons during the 20th century.
After notorious revolutionary leader Pancho Villa's raid on Columbus, New Mexico, General John Pershing and his 150,000 man cavalry set out to get Villa.
During World War II, more than a thousand women signed up to fly with the U.S. military as WASPS.
After the Soviet blockade of West Berlin, British and American pilots delivered tons of food and fuel to the German city by airplane for nearly a year.
Winner, 2010 Peabody Award --- The 1968 My Lai massacre, its subsequent cover-up, and the soldiers who broke ranks to bring the atrocity to light.
In the early 1830s, Texas, ruled by Mexico, held 20,000 U.S. settlers and 4,000 Mexican Tejanos, forcing residents to pick sides.
During the defining months of the offensive against Germany, American forces faced a moral and strategic dilemma.