The United States has 113 protected areas known as national monuments. The President of the United States can establish a national monument by presidential proclamation, and the United States Congress can by legislation. The Antiquities Act of 1906 authorized the president to proclaim "historic landmarks, historic and prehistoric structures, and other objects of historic or scientific interest" as national monuments. Concerns about protecting mostly prehistoric Indian ruins and artifacts—collectively termed antiquities—on western federal lands prompted the legislation. Its purpose was to allow the president to quickly preserve public land without waiting for legislation to pass through an unconcerned Congress. The ultimate goal was to protect all historic and prehistoric sites on U.S.