A National Historic Landmark (NHL) is a site recognized by the government of the United States as having particular historical significance. As of early 2023, there are more than 2,600 NHLs in the U.S. today, including"historic buildings, sites, structures, objects, and districts" This designation may be conferred by the National Park Service. National Historic landmarks may be publicly or privately owned, in contrast with National Parks (which are all publicly owned), and roughly half of the recognized NHL sites are privately held.
Ronald Reagan is apparently not associated with any National Historic Landmarks, while the birthplace of Richard Nixon is a National Historic Landmark in California. At least five National Historic Landmarks in Illinois are connected with Abraham Lincoln.