National Historic Sites and National Historical Parks are designations for officially recognized areas of national historic significance. They are usually owned and managed by the federal government. A National Historic Site usually contains a single historical feature directly associated with its subject. A National Historic Park generally extends beyond single properties or buildings, including a mix of historic and later structures and sometimes significant natural features.

As of 2024, there are 63 National Historic Parks and 85 National Historic Sites, most of which are managed by the National Park Service. Some federally designated sites are owned by local authorities or privately owned but are authorized to request assistance from the National Park Service as affiliated areas. One property is managed by the U.S. Forest Service — the Grey Towers National Historic Site in Pennsylvania.

Beginning on October 15, 1966, all historic areas in the National Park Service, including National Historic Parks and National Historic Sites, were automatically listed on the National Register of Historic Places. There are also about 90,000 National Register of Historic Places sites, most of which are neither owned nor managed by the National Park Service. Of these, about 2,500 have been designated at the highest status as National Historic Landmarks.

After its founding in 1916, the National Park Service oversaw primarily scenic and natural sites, including national parks and national monuments. Historians soon began recommending the preservation of sites relating to human history. Congress created the Colonial National Monument in 1930 to protect the Jamestown Settlement and Yorktown Battlefield in Virginia as one of the first new historical areas, and it was renamed a national historical park in 1936. Morristown National Historical Park, the 1779-1780 winter encampment of the Continental Army in New Jersey, was established as its largest historical area on March 2, 1933. The U.S. House committee noted that the new designation was logical for the area and set a new precedent compared to National Military Parks, which the War Department then managed. The park’s establishment allowed the National Park Service to have an administrative, historical program with professional historians. President Franklin D. Roosevelt reorganized the agency also to oversee memorials and military parks with historic significance later in 1933, substantially broadening the National Park Service’s mandate.

While the National Park Service is best known for its expansive scenic parks, like Yellowstone and Yosemite National Parks, more than half of the areas it manages were established to commemorate important people and events in American History. Many of these historic sites offer an intersection between the beauty of natural landscapes and historical events, bringing in millions of visitors annually.