John Muir was a pioneering preservationist who is widely credited with helping to establish the modern environmental movement. He was an early advocate for the preservation of wilderness in the United States and is often referred to as the 'Father of the National Parks'. Muir was also a prolific writer, publishing several books and articles on the subject of conservation. His work helped to shape public opinion and policy on the environment, and he is remembered today as one of the most influential figures in the history of conservation.