It is fair to point out that the alternative to American conquest and rule was not independence, it was rule by some other colonial power.
This was the high tide of colonialism, and no attractive territory occupied by brown people would have been allowed to go free.
Most likely it would have been the Germans moving in, as they were the most aggressive at the time, being late out of the gate in the colony race and desperate to catch up.
Ethiopia & Liberia were free; when enough of the brown people picked up guns, they all became free.