Stand, ignore the South-hating, euro-trading scum. Life is too short to waste on guys like him. Let him snark. He isn't smart enough, or patient enough, to do the study and research to do any real damage. (He can't. The weakness of his position is, he has to ignore new documentary evidence that things weren't like he heard in "publick screwel".) Guys like Mark Neely and Eric "the Red" Foner do more damage -- and "Red" McPherson -- by running around helping scum like Slick "contextualize" (politicize) American history to help the PC 'Rats vacuum up more ignorant votes. I think you saw that series of posts where I linked to the National Park Service webpages about Gettysburg, where McPherson and Foner had helped PC trolls in the Interior Department re-write some of the public displays on the battlefield, to politicize the battle and push the Clintonista/Marxist "it was all about slavery" line.
I've got the guy you responded to on bozo filter anyway. Just ignore him. Plonk and ignore.
Salon's "TableTalk" was a forum teeming with loathsome West Coast PC troglodytes, but at least they had a bozo filter that worked -- you literally didn't have to look at the poster's stuff if you didn't want to. Just invoke the filter, and the guy's stuff was blipped and replaced with placeholders.