The difficulties of transport in military operations are constantly mentioned. This includes finding horses or mules, of training them, and of feeding them once found. Wagons cannot move through mud, and sometimes not even horses or marching men can. Both kinds of road were extremely unpleasant. Wagon trains congest and obstruct roads.
Artillery also obstructs roads and hinders movement.
In Northern Virginia, Grant disposed of excess artillery to free up the roads for supplies. Railways were obviously the most valuable military transport. The Civil War was the first war in which they played a role. They were ripped up and laid down everywhere in the theatre of operations. The speed with which a destroyed railway could be restored to service was amazing.