From PBS - In the midst of an economic catastrophe and then a world war, the national parks provide a source of much-needed jobs and then much-needed peace; the park idea changes to include new places and new ways of thinking; and in Wyoming, battle lines are drawn along the front of the Teton Range. To battle unemployment in the Great Depression, Franklin D. Roosevelt creates the Civilian Conservation Corps, which spawns a "golden age" for the parks through major renovation projects. In a groundbreaking study, a young NPS biologist named George Melendez Wright discovers widespread abuses of animal habitats and pushes the service to reform its wildlife policies. Congress narrowly passes a bill to protect the Everglades in Florida as a national park - the first time a park has been created solely to preserve an ecosystem, as opposed to scenic beauty. As America becomes entrenched in World War II, Roosevelt is pressured to open the parks to mining, grazing and lumbering. The president also is subjected to a storm of criticism for expanding the Grand Teton National Park in Wyoming by accepting a gift of land secretly purchased by John D. Rockefeller Jr.