Which answer correctly explains how the railroads provided an advantage in the Civil War? The Union had more railroad lines and so needed many more troops than the Confederacy to protect the trains. The Union had more railroads and could move supplies and soldiers more quickly than the Confederacy. The Confederacy used a railroad blockade to cripple the flow of southern goods to the North. The Confederacy placed spies in the railroad companies to report on troop and supply movements.