The Indigenous peoples of the Americas are the inhabitants of the Americas before the arrival of the European settlers in the 15th century, and the ethnic groups who now identify themselves with those peoples. Many Indigenous peoples of the Americas were traditionally hunter-gatherers and many, many groups practiced aquaculture and agriculture. While some societies depended heavily on agriculture, others practiced a mix of farming, hunting, and gathering. In some regions, the Indigenous peoples created monumental architecture, large-scale organized cities, city-states, chiefdoms, states, kingdoms, republics, confederacies, and empires. Many parts of the Americas are still populated by Indigenous peoples; some countries have sizeable populations, especially Bolivia, Canada, Chile, Ecuador, Guatemala, Mexico, Peru and the United States. Many also maintain aspects of Indigenous cultural practices to varying degrees, including religion, social organization, and subsistence practices. Like most cultures, over time, cultures specific to many Indigenous peoples have evolved to incorporate traditional aspects but also cater to modern needs. Some Indigenous peoples still live in relative isolation from Western culture and a few are still counted as uncontacted peoples. Native Americans, also known as American Indians, First Americans, Indigenous Americans, and other terms, are the indigenous peoples of the United States, including Hawaii and territories of thACe United States, as well as Northern Mexico and Canada and other times just the mainland United States. There are 574 federally recognized tribes living within the US, about half of which are associated with Indian reservations. "Native Americans" are indigenous tribes that are originally from the contiguous United States, along with Alaska Natives. Indigenous peoples of the United States who are not American Indian or Alaska Native include Native Hawaiians, Samoans, and Chamorros.