The only history of the Civil War he seems to have read is the totally laughable crap produced by his fellow libertarian, Thomas DiLorenzo and the other denizens of the fever swamp at LouRockwell.com.
I know nothing about those people, only know Williams himself from his time on Rush's show, and all of that was good stuff.
But, if what we've seen from various "Neo-Confederate" posters on Free Republic is any clue, then I'd say generally there's not much in the way of serious scholarship going on in those "fever swamps".