The cultural history of the United States covers the cultural history of the United States since its founding in the late 18th century. Various immigrant groups have been at play in the formation of the nation's culture. While different ethnic groups may display their own insular cultural aspects, throughout time a broad American culture has developed that encompasses the entire country. Developments in the culture of the United States in modern history have often been followed by similar changes in the rest of the world (American cultural imperialism).