Christopher Gabel talked about the importance of railroads and steam-powered locomotives to the the Union and Confederate armies during the U.S. Civil War. Professor Gabel explained how railroads made the scale of the Civil War possible and described how and why the Confederacy’s powerful railroad system broke down as the war progressed.
http://www.c-span.org/video/?320456-1/discussion-railroads-civil-war
That was quite interesting.