The epic battle waged over dinosaur fossils by rival paleontologists in the American West.
A biography of the last outlaws of the American Wild West
At the height of segregation, an unlikely alliance between a black medical genius and a white surgeon led to a pioneering medical breakthrough.
The Pennsylvania Railroad Company accomplished an enormous engineering feat, but destroyed a great architectural monument.
Begun during the Civil War, the transcontinental railroad employed 20,000 men, mostly immigrants, who built the iron road with their bare hands.
In the early 1830s, Texas, ruled by Mexico, held 20,000 U.S. settlers and 4,000 Mexican Tejanos, forcing residents to pick sides.
Major Walter Reed's discovery in 1900 that mosquitoes spread yellow fever halted an outbreak and led to the disease's eventual eradication.
Originally settled as a mail stop, Las Vegas changed from an Old West vacation town, to a mafia haven, to the "Atomic City" and "Sin City."