John Muir (1838-1914) was a Scottish-born American naturalist, preservationist, and explorer. Also known as “John of the Mountains,” he was active in the late 1800s and early 1900s, using his writings to persuade the American public and politicians to preserve America’s wilderness. He lived in the United States, exploring and detailing his discoveries and experiences across his various works. He is the founder of the environmental group, the Sierra Club, and his advocacy for the environment led to the establishment of the National Parks.