The United States is home to many cultures and a wide variety of ethnic groups, traditions, and values. Aside from the Native American, Native Hawaiian, and Native Alaskan populations, nearly all Americans or their ancestors immigrated or were imported as slaves within the past five centuries. Mainstream American culture is a Western culture largely derived from the traditions of European immigrants with influences from many other sources, such as traditions brought by slaves from Africa. More recent immigration from Asia and especially Latin America has added to a cultural mix that has been described as both a homogenizing melting pot, and a heterogeneous salad bowl in which immigrants and their descendants retain distinctive cultural characteristics.