Wargame Shop have released a print-and-play 3D Battle of Manassas boardgame.
From their announcement:
Wargame Shop release the first in a new series of American Civil War PDF downloadable games from wargamesdownload.com First Manassas or Bull Run has been designed so that the gaming board can be played either straight from the printer in 2D or it can be constructed into a 3D landscape. The game comes with a ACW rule set Brothers At Arms that will be common throughout the series of battles that start in 1861 and progress through to 1865. All counters and even tile dice are included in the download.