In 1872, the U.S. Congress established the first national park in the United States with the creation of Yellowstone National Park.
Citation:
Richert, Lucas Paul. "Yellowstone National Park founded".
The Literary Encyclopedia. First published 01 February 2009
[http://www.litencyc.com/php/stopics.php?rec=true&UID=5972, accessed 19 May 2013.]