Ironically the Cherokees were dispossessed by the slaver state of Georgia when it existed as a part of the Union. A culture of parasites is always eager to take from others.
But yes, Northerners did horrible things as well to Indians from one end of the continent to the other. However your point is absurd.
The Confederacy was created SOLELY to preserve slavery. Without slavery it had no reason to exist.
The Union was not created to destroy Indians. Hypocritical and racist Whites did not extend principles that included all human beings to in fact include all human beings, and so justified killing Indians and, for the worst of them, slavery as well. Wise Americans saw these attitudes as a contradiction and used our founding principles to criticize our practice. Our culture is a work in progress, slowly improving the practical application of the principles in our Declaration and Constitution.
No such growth was possible for the parasitic culture of the South, and so in honoring its heritage it honors those devoted to slavery and racism.