The National Park Service, or NPS, is a federal agency within the U.S. Department of the Interior. The U.S. Congress made Yellowstone America’s first national park in 1872. In the years that followed, environmentalists including John Muir lobbied for wilderness preservation throughout the American West with the creation of several more national parks and monuments. President Woodrow Wilson established the National Park Service in 1916 to consolidate management of America’s federal parklands under one agency. The National Park Service today manages 84 million acres across all U.S. states and territories, and has served as a model for countries around the world.