The latter half of the 19th century saw the "golden age" of the American cowboy; newly-built railroad lines made it easier to transport cattle from the western plains to the east coast, where they could fetch top dollar. As these photos reveal, a cowboy's life was a hard one, but living freely on America's western frontier nevertheless appealed to thousands of men.
These photos were taken across the American West between the late 1800s and the early 1900s.
In the early 1830s, Texas, ruled by Mexico, held 20,000 U.S. settlers and 4,000 Mexican Tejanos, forcing residents to pick sides.
Three years before the Gold Rush, 87 pioneers took a shortcut westward to California, only to get caught in the snows of the Sierra Nevada.
Robert Noyce's invention of the microchip launched the world into the Information Age.
A man who symbolized African American equality fought a proponent of Hitler's Aryan racial theories on the eve of World War II.
P.T. Barnum -- huckster, con man, promoter, entertainer and founder of "The Greatest Show on Earth".
The contradictory history of a dam that became a statement of American power and prestige.
A six-hour series on how the West was lost and won, from the Gold Rush in 1848 until Wounded Knee in 1893.
The life of the legendary photographer, known best for his black and white images of the wilderness of the American West.