A blogger has been posting blog entries on the Gettysburg campaign, as if he were writing in late June and early July 1863. Gettysburg experts probably won't learn anything new, but it's a fun idea and perhaps a good way to get those younger relatives interested in the campaign and battle.
I've linked the first entry. There are succeeding entries for each day through the battle.
http://rightwingnuthouse.com/archive.../june-27-1863/