Canadians and Americans mistakenly referred to all the Niitsitapi bands as "Blackfoot", but only one nation was called Siksika or Blackfoot. Due to language and cultural patterns, anthropologists believe the Niitsitapi did not originate in the Great Plains of the Midwest North America, but migrated from the upper Northeastern part of the country. They coalesced as a group while living in the forests of what is now the Northeastern United States. They were mostly located around the modern-day border between Canada and the state of Maine. By 1200, the Niitsitapi were moving in search of more land. They moved west and settled for a while north of the Great Lakes in present-day Canada, but had to compete for resources with existing tribes. They left the Great Lakes area and kept moving west.
From the Great Lakes area, they continued to move west and eventually settled in the Great Plains.
Adopting the use of the horse, the Niitsitapi established themselves as one of the most powerful Indian tribes on the Plains in the late 18th century, earning themselves the name "The Lords of the Plains."