In this In4 video segment, Historian Garry Adelman explains the various types of fortifications used by both sides during the Civil War. This video is part of the Civil War Trust's In4 video series, which presents short videos on basic Civil War topics.

Historian Roger Bailey discusses the revolution in naval weapons and propulsion that took place before the Civil War, and the rise of ironclads, torpedoes, and submarines in the wartime navies.

Historian Garry Adelman explains why soldiers fought in "line of battle." This video is part of the American Battlefield Trust's In4 video series, which presents short videos on basic Civil War topics.