Robert Marshall, Aldo Leopold and Howard Zahniser dedicated their lives to protect the shrinking American wilderness. As a result, the Wilderness Act passed in 1964.
When an earthen dam broke without warning, a small city in Pennsylvania was swept away in a wall of water over 30 feet high.
Vivid memories of those trapped in the terrifying temblor of 1906 that killed thousands of Californians.
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 New Deal program CCC put three million young men to work in camps across America.
Today one of the most-recognized figures in American literary history, poet Walt Whitman was denounced by critics in his own time.
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.
In 1934, American polar explorer Richard Byrd became the first to experience winter in Antarctica's interior.
Native Alaskans, oil company representatives, environmentalists, politicians, and others tell the story of the 800-mile pipeline.