List of national memorials of the United States
National memorial is a designation in the United States for an officially recognized area that memorializes a historic person or event. As of September 2020 the National Park Service (NPS), an agency of the Department of the Interior, owns and administers 31 memorials as official units and provides assistance for 5 more, known as affiliated areas, that are operated by other organizations.
Source: Wikipedia — List of national memorials of the United States (CC BY-SA 4.0)