When my son was around ten we joined a Military History book club because of his interest in that topic. When the Ken Burns documentary on the Civil War came out we watched it together and I was proud that he had read at least half the books Burns cited as reference material, including Killer Angels about Gettysburg.
I assume that you live in a region where there are Civil War battlefields. Virginia is awash with landmarks. My roots are West Virginia and Kentucky, and my relatives fought on both sides in Virginia… in the legislature. Two fought for the secession and two for staying together. I have a book about that written by another relative in the 1880s.
As for Gettysburg, it is impossible to really grasp what happened there without visiting it in person. Books help tell part of the story, but seeing the long ascent across the open field, Pickett’s Charge, …it doesn’t take much to imagine the heartbreak of that day’s horror.
I will look for your Apprentice Killers: The War of Lincoln and Davis. And yes, Meade and Grant were very different men.