On August 25, 1916, President Woodrow Wilson signed the act that created the National Park Service, the fundamental purpose of which "is to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations." One hundred years later, the National Park System encompasses more than 400 sites and 84 million acres. More than 300 million people visited National Parks in 2015.