They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as intact political communities. The terms used to refer to Native Americans are controversial; according to a US Census Bureau set of home interviews, most of the respondents with an expressed preference refer to themselves as American Indians or Indians. In the last years, Afro-Eurasian migration to the Americas has led to centuries of conflict and adjustment between Old and New World societies. Most of the written historical record about Native Americans was made by Europeans after their immigration to the Americas. Their cultures were quite different from those of the agrarian, proto-industrial immigrants from western Eurasia.