A few years ago, I served as one of the historical advisers for the movie Glory, which told the story of the 54th Massachusetts Colored Infantry and its brave and calamitous attack on Fort Wagner in the summer of 1863. This sort of consultation makes for a very agreeable job: You get paid to show off, while never suffering the faintest pinch of real responsibility.

The moviemakers supplied me with a copy of the script, and I went through it picking what nits I could find—the 54th carried Enfield Rifle Muskets, not Springfields, that sort of thing—but there was one omission that struck me as being of real significance. The script had the 54th launching its doomed assault cold, with no artillery preparation. I said that there should be at least some suggestion that Fort Wagner had been subjected to intense bombardment; it was true that the works had not been nearly so softened as their besiegers believed, but succeeding generations of artillerists would make the same error, right on down to our own time. The attack was a disastrous mistake, but it wasn’t a crazy mistake.

And when I saw the movie, sure enough: Before the charge, there is a glimpse of a smoke-shrouded host of ironclads and square-riggers, standing off Charleston, pumping shells into the Rebel fort.

I loved that scene—and why wouldn’t I have? It’s pretty satisfying to summon up an entire Union fleet with a phrase. But reading through Past Imperfect, the new book in which historians discuss historical movies, I discovered my enthusiasm rested on something more than my brief endowment with godlike powers.

Now, it happens that I detest two of the greatest historical films ever made: Birth of a Nation, which reflects at its ugliest the tacit, Mephistophelean deal in which the North made amends to the postwar South by pretending that both sides had been defending causes of equal virtue; and Gone With the Wind, which carries the same message, albeit in less raw form, and in which I don’t give a damn about Scarlett three hours earlier than Rhett doesn’t. Yet both these movies contain scenes that are thrilling to me in their ability to retrieve the past. The battles in Birth of a Nation give one the eerie sense of watching Civil War newsreels, and Scarlett O’Hara’s red dress scudding back and forth through the endless rows of Confederate wounded in the Atlanta yards reveals the breadth of the struggle with both grandeur and economy.

Almost every historical movie I’ve ever seen, even the worst turkeys, has at least one scene that makes plausible the idea of a living past. We all know the past happened, of course, but that is a different thing from feeling that it did. Old photographs have the two-edged power to make the past both more immediate and more distant, while artifacts—composed, cold, inevitably out of