Let me try to jog your memory about Antietam...
Do the terms Dunker Church, Cornfield, Sunken Road, and, most emblematic of all, Burnside's Bridge ring a bell? Viewing it not too long after the Burns series, I really did get the goosebumps predicted by the NPF. Gettysburg too, but the single-day Antietam battle is much easier to get your mind around than the three day ebb-and-flow of Gettysburg.
I might have been 12 or 13, so it was a long time ago. Sunken Road sounds familiar, though.
I've been to several of the Parks, but would love to just see them all. I'd also like to see the Grand Canyon, and have never made it. I saw it by air once, but that hardly counts.