Mount Rushmore, one of the National Memorials of the United States http://commons.wikimedia.org/wiki/File:Mount_rushmore.jpg Larry Jogerst
National Memorials of the United States are a list of protected areas commemorating historic persons and/or events related to the United States of America. They do not necessarily need to have the word "national" attached to them to be part of the list of national memorials.
There are presently 28 national memorials in the United States. They are owned and administered by the National Park Service, with another 5 administered by other agencies, but with assistance from the National Park Service. All national memorials within the National Park System are automatically listed on the National Register of Historic Places while not all affiliated areas are.
Lincoln Memorial, District of Columbia http://commons.wikimedia.org/wiki/File:Lincoln_Memorial_Close-Up.jpg David Bjorgen
The Washington Monument, completed in 1884, was the first national memorial while the most recent is the World War II Memorial, dedicated on 2004.