But not all were in chains, or had a terrible life. Heck, lots of whites had a terrible life, I had ancestors that were indentured servants - little more than slaves themselves. Many slaves earned money, some donating it to the Confederate government, and others fought for the Confederacy. I will not begin to denigrate their service as is the manner of some - regardless of the reason they fought, they fought for what they believed. And in the rose-colored glasses worn by many, it obviously was something other than slavery.
[S]lavery alone would have been enough reason to send troops.
Why, if the Constitution allowed it? I wish that they had passed an amendment that ended it, and that the events leading to secession never happened. As a southerner, I'm sure you are quite familiar with the existing bad-blood that lingers today, and the racism and holier-than-thou regard for the South you aptly describe. Would that be there if the war & Reconstruction hadn't happened?
No it would not. But again, I would be willing to risk all rather than allow a race to be held in bondage within the borders of America. You seem to be soft-pedaling the condition of blacks under slavery. No rational observer would hint that they were doing just fine under white domination.
You guys always try to say that slavery is no big deal. Will you volunteer to be my slave to prove it?