As news spread that the Americans were leaving Saigon, thousands of South Vietnamese descended upon the U.S. Embassy, desperate for a chance to get out before the North Vietnamese arrived.
As North Vietnamese tanks rolled into Saigon, eleven U.S. Marines found themselves on the roof of the American Embassy with no U.S. helicopters in sight.
In the early 1900s, President Theodore Roosevelt worried that unless America's forests were protected and regulated, the nation's forests would soon disappear.
