Why were the native Americans willing to make the treaty of greenville with the US

The American Indians who became signatories agreed to relinquish all claims to land south and east of a boundary that began roughly at the mouth of the Cuyahoga River. It ran southward to Fort Laurens and then turned westward to Fort Loramie and Fort Recovery. The whites agreed to relinquish their claims to land north and west of the line, although the American Indians permitted the Americans to establish several trading posts in their territory.