The idea of the national park is 150 years old today. On March 1, 1872, President Ulysses S. Grant signed an act setting aside Yellowstone as a public park. It wasn’t the plan, but it ended up being the first of many. Over the century and a half that followed, the United States added another 62 parks and hundreds more federally-protected scenic areas, monuments, seashores and rivers.
The concept of the national park has been called “America’s best idea,” but as Yellowstone has shown, the idea itself has evolved dramatically over the years.