The National Park Service (NPS) is an agency of the United States federal government that manages all U.S. national parks, many American national monuments, and other conservation and historical properties with various title designations. It was created on August 25, 1916, by Congress through the National Park Service Organic Act and is an agency of the United States Department of the Interior. The NPS is charged with a dual role of preserving the ecological and historical integrity of the places entrusted to its management while also making them available and accessible for public use and enjoyment.