The dramatic story of the country's first subway.

A riveting account of the event that helped give rise to the modern American militia movement.

She set out to save a species...us. An intimate portrait of the woman whose groundbreaking books revolutionized our relationship to the natural world.

Part 1 of 3. President Woodrow Wilson vowed to keep the U.S. out of World War I after hostilities erupted in Europe in August 1914. It was a promise he kept until 1917, when the Germans resumed "unrestricted submarine warfare"— a policy it had started and then stopped in 1915 — and began sinking U.S. ships. An intercepted telegram also showed Germany trying to convince Japan and Mexico to declare war on America.

An account of an incident at a Titan II missile complex in Damascus, Ark., in 1980 that almost caused the explosion of a ballistic missile carrying a nuclear warhead 600 times more powerful than the bomb that destroyed Hiroshima. The near-calamity was kicked off when a socket fell from the wrench of an airman performing maintenance in a Titan II silo and punctured the missile, releasing a stream of highly explosive rocket fuel.

On April 19, 1995, Timothy McVeigh, a former soldier deeply influenced by literature and ideas of the radical right, killed 168, and injured 675 others.

Part 2 of 3. America's entry into World War I is recalled, including the breathtaking speed of mobilization and the profound transformations required for America to play a central role in the conflict.

Part 3 of 3. In the fall of 1918: a major American offensive that could bring a swift end to the war, a lost U.S. battalion surrounded by German forces, a deadly flu epidemic on the homefront.