Who is Atiwaneto from The World Turned Upside Down: Indian Voices from Early America and what is their importance?

Atiwaneto was an Abenaki Indian who delivered a harsh speech to a Massachusetts emissary named Phineas Stevens in 1752. Atiwaneto berated Stevens for Massachusetts' characterization of the Abenaki as a bad people and Atiwaneto forbade any colonists from encroaching further on Abenaki land.