John Muir was a Scottish-American conservationist who founded the Sierra Club in 1892. He helped to protect many areas in the United States by advocating for the creation of national parks and wilderness areas. Some of his most notable works were about his explorations of nature, especially in the Yosemite Valley and Sierra Nevada mountains of California. He has had a significant and ongoing legacy of environmental protection in the United States through organizations like the Sierra Club that continue his efforts over a century later.