Conversation so far:
When was the Blackfoot confederacy started ?
Anthropologists believe the Blackfoot Confederacy migrated from the upper Northeastern part of the country.
Does any record exist of the Blackfoot Confederacy's early history ?
In the first half of the 18th century, Blackfoot Confederacy acquired horses and firearms from white traders and their Cree and Assiniboine go-betweens.
How did the Blackfoot early society worked ?
Historically, the member peoples of the Blackfoot Confederacy were nomadic bison hunters and trout fishermen, who ranged across large areas of the northern Great Plains of western North America

Question: Where do they think they originate ?
Self-contained rewrite: Where do anthropoligists think the Blackfoot Confederacy originate?