Douglas would repeat what Lincoln said about racial equality at Charleston in debates to come, usually in support of his claim that Lincoln varied hi… - Brooks D. Simpson

I think it's time for all this discussion about the proper display of the Confederate flag, which in some quarters appears to obscure the enormity of the massacre at Charleston, to get to the heart of the matter. You tell me. Should the Confederate battle flag, including its versions as the Army of Northern Virginia flag, the Army of Tennessee flag, and the Confederate navy jack, be flown outside, period? Do you favor the removal of the Confederate flag flying on the grounds of the South Carolina State House? Why? If you believe that the flying of the Confederate battle flag on the grounds of the South Carolina State House should cease, are there any conditions when a Confederate battle flag should appear outside? Should the Confederate battle flag be banned from public display elsewhere? T-shirts, bumper stickers, headgear? Are your restrictions limited to the Confederate battle flag alone, or do they extend to other flags flown by the Confederacy, such as the trio of national flags?

Ranting about "political correctness" is best read as "I can't really deal with the merits of your interpretation, so I'll deride it largely because it doesn't reinforce my own preferences and prejudices."

In 1864, black Union troops were involved in operations against Lee's army outside Richmond and Petersburg, and some of them are taken prisoner. Lee puts them to work on Confederate entrenchments that are in Union free-fire zones. When Grant gets wind of this, he threatens to put Confederate prisoners to work on Union entrenchments under Confederate fire unless Lee pulls out. So Grant was willing to embrace an eye-for-an-eye, tooth-for-a-tooth retaliation policy based upon Confederate treatment of black prisoners. For Grant, it was the color of the uniform, not the skin, that mattered.