American troops were sent abroad in the 1790s to steal native American land.

steal

v.

To take (the property of another) without right or permission.

v.

To present or use (someone else's words or ideas) as one's own.

v.

To get or take secretly or artfully: steal a look at a diary; steal the puck from an opponent.

None of those things apply.
It's not theft nor a whit supremacist attitude, you have failed to prove me right or yourself wrong on a single point yet you claim victory, that is sophistry.
Zinn's book is anti American hogwash, political tripe.