In the United States, a National Heritage Area (NHA) is a site designated by Act of Congress, intended to encourage historic preservation of the area and an appreciation of the history and heritage of the site. There are currently 55 NHAs, some of which use variations of the title, such as National Heritage Corridor. The first NHA created, the Illinois & Michigan Canal National Heritage Corridor, located in Illinois, was signed into legislation by President Ronald Reagan on August 21, 1984.