I grew up in the Gettysburg area, one of my brother's friends is a battlefield historian, and while she wasn't available, he was and he showed us the actual wall that was there during Pickett's charge, and a lot of other things.
In shop class, we had a can for bullets - it wasn't uncommon to get a board from a wood lot that had seen action during the war. You could easily tell Confederate from Union bullets - Confederate bullets were round, Union were hollow point.