Good advice.Excellent advice. It's exactly the approach I'd advise anyone to take, and which I've taken myself. Read widely. Read the primary sources. Dig a little. Don't let anyone tell you what to think, decide for yourself what the facts reveal.
I have found a good practice to be to limit perspectives on the coming of the war only to antebellum literature. I.e., to get inside the antebellum American minds, Northern, Southern, Western, Southwestern, etc. I do not ignore contemporary or past writers about the war, but I note especially their bibliographies to see what they have read. It was the growing awareness of the lack of any references or only few references to De Bow's Review that has caused me to question their qualifications to evaluate what anyone believed in the South from 1845-1861. And the almost total lack of awareness of the Pacific Railroad Surveys is a dead giveaway. When I see no reference whatsoever to them, I say to myself, "This fellow is not really equipped to deal with the coming of the war." Sadly, that includes McPherson and Freehling and Dew, et al. And I suspect but do not know that it might include UB and Lefty and a few others.