The most likely reason for someone with a European genealogy to have genetic ancestry from the Americas is a previously unknown Native American ancestor. This may be from North or South America. In some cases, the source may include people who were taken to Europe by European explorers during the early years of European Colonization.

When considering what genetic ancestry from America means to you and your research, you should consult the full list of reference populations for the America Continental group and each of its Subcontinental groups.