In 1934, American polar explorer Richard Byrd became the first to experience winter in Antarctica's interior.
John Wesley Powell's epic journey into the unknown Grand Canyon was filled with adventure as his team mapped the Colorado River for the first time.
High on a granite cliff in South Dakota's Black Hills tower the huge carved faces of four American presidents: George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt.
The coal miners' battle for dignity led to the largest armed insurrection since the American Civil War.
Native Alaskans, oil company representatives, environmentalists, politicians, and others tell the story of the 800-mile pipeline.
In 1927, the Mississippi River flooded from New Orleans to Illinois, leaving a million people homeless and leading to a major black migration to the North.
The contradictory history of a dam that became a statement of American power and prestige.