By the Act of March 1, 1872, Congress established Yellowstone National Park in the Territories of Montana and Wyoming 'as a public park or pleasuring-ground for the benefit and enjoyment of the people' and placed it 'under exclusive control of the Secretary of the Interior.' The founding of Yellowstone National Park began a worldwide national park movement. Today more than 100 nations contain some 1,200 national parks or equivalent preserves. Quick History of the National Park Service (U.S. National Park Service)