John Muir was born in Scotland and emigrated to Wisconsin as a young boy. Muir spent much of his adult life wandering in, and fighting to preserve, the wilderness of the western United States, especially California. His efforts led to the creation of Yosemite National Park, Sequoia National Park, and millions of other conservation areas.

Rachel Carson was born in rural Pennsylvania. After working for the U.S Fish and Wildlife Service, Carson published "The Seas Around Us" and other books. He most famous work was the controversial "Silent Spring" in which she described the effect that pesticides were having on the environment. Eventually, Carson's observations were proven correct and pesticides like DDT were eventually banned. Carson was considered the to be the woman that started the modern environmental movement.

Edward was one of America's most dedicated and outrages environmentalist. Born in Pennsylvania, he is best known for his passionate defense of the desert of America's Southwest. Abbey wrote "Desert Solitaire", which was a description of his experiences in the Southwest. He wrote many books which details all of Abbey's radical leanings. He advocated aggressive action against environmental destruction and ended up being on of the world's most celebrated choices of political dissent and environmental preservation.

Aldo Leopold is considered by some to be the godfather of wilderness conservation and of modern ecologists. After studying forestry at Yale University, he worked for the U.S. Forest Service. Although he was originally asked to kill bears, cougars, and other predators on federal land because of protests from local ranchers, he later adopted a different approach to wilderness management. His best-known book, "A Sand County Almanac", remains one of the most eloquent pleas for the preservation of wildness ever written.

Julia Hil is one of the most committed environmentalists alive today. After nearly dying in a car crash in 1996, she dedicated her life to environmental causes. For almost two years, Hill lived in the branches on an ancient redwood tree in northern California to save it from being cut down. Her tree-sit because an international cause that attracted great public attention and Hill remains involved in environmental and social causes.

Henry David Thoreau waste of America's first philosopher-writer-activists, and still remains as one of the most influential. In 1845, Thoreau spent two years living a life of simplicity in a small house he build near the shore of Walden Pond in Massachusetts. Those two years were his inspiration for "Walden", or "A Life in the Woods", a meditation on life and nature that is considered a must-read for all environmentalists. His thoughtful observation of man, society, and nature helped him become one of America's first and most ardent environmentalists.

Even though he was a hunter, Theodore Roosevelt was one of the most active champions of wilderness preservation in history. As governor of New York, he outlawed the use of feathers as clothing adornment in order to prevent the slaughter of some birds. While president of the U.S., Roosevelt set aside hundreds of millions of wilderness acres, actively pursued soil and water conservation, and created over 200 national forests, national monuments, national parks and wildlife refuges.

Gifford Pinchot was the son of a timber baron who later regretted the damage he had done to America's forests. Because of this, Pinchot was studied forest for many years and was appoint by President Grover Cleveland to develop a plan for managing America's western forests. Theodore Roosevelt later asked him to lead the U.S. Forest Service. He publicly batted John Muir over the destruction of wilderness tracts like Hetch Hetchy in California, while also being condemned by timer companies for closing off land to their exploitation.

Chico Mendes is best known for his efforts at saving the rainforest of Brazil from logging and ranching activities. Mendes came from a family pf rubber harvesters who supplemented their income by sustainably gathering nuts and other rainforest products. When he was informed of the devastation of the Amazon rainforest, he helped to ignite international support for its preservation. His activities, however, drew the ire of powerful ranching and timber interests. Mendes was murdered by cattle ranchers.