SPI accompanied the game's release with an article in its house magazine Moves called "The Importance Of Being Buford", which covered the cavalry delaying action on the first morning, when John Buford's handful of Union cavalrymen held off Henry Heth's division long enough for the Iron Brigade to come up. Now, this worked historically because Buford's men were equipped with breechloading carbines and Heth was a moron, but that kind of stupid's something you can't count on when you're playing the game. I hadn't really appreciated this aspect of the battle before, and it made me like Shaara's The Killer Angels all the more for spending a chapter on General John Buford.
What brings all this to mind is an article in the Smithsonian that does an excellent job of presenting the battle in multimedia form. Well worth looking at.
(h/t Jeff Quinton)