[wideawake]

Northern opposition to the extension of slavery into western territories was based on the precept that the west should be for only the white man

Oh, really.

A pity none of the "Northern opposition" in Congress bothered to mention that federal lands were only for white people at the time.

Presumably Congress forgot that the Choctaw weren't white.

[equalitybeforethelaw]

“A pity none of the “Northern opposition” in Congress bothered to mention that federal lands were only for white people at the time.

Presumably Congress forgot that the Choctaw weren’t white.”

Please reread the part about concentrating or killing.
Blacks were to be kept out and Indians either concentrated or killed. So who was the racist in 1860? There were many reservations created Congress. This would be understood as concentrating a population. They put limits on tribes and recognized their independence. They didn’t invite them to the dance though.

[Non-Sequitur]

A pity none of the "Northern opposition" in Congress bothered to mention that federal lands were only for white people at the time.

And Southerners were fine with black people in the territories if, and only if, they were the property of someone. My how noble of them. </sarcasm>