Why did the iroquois confederacy fail to get the land west of the allegheny mountains that had been promised to them by the british?
the british government went back on their promise.
the american colonists began to move west.
the iroquois confederacy no longer wanted the land.
the spanish captured the territory.
the french colonists recaptured the land.

The correct answer is "The American colonists began to move west".

Explanation:

As part of the treaty of Easton, the British promised to prevent settlement on the land west of the Allegheny Mountains and leave them for the Native Americans members of the Iroquois Confederacy. However at the end the British failed to gave the lands to the Native Americans since the American colonists began to move west and it would be too challenging to regulate trade and taxes if Native Americans would occupied the land west of the Allegheny Mountains.

lincoln declared that slavery should not be allowed to spread into the new states, and of course this angered the south at the time.

i would go with the last one