How were railroads used in the civil war?

The civil war was the first war in which railroads were a major factor. The 1850s had a huge growth in the railroad industry.

The Civil War was the first war in which railroads were a major factor. The 1850s had seen enormous growth in the railroad industry so that by 1861, 22,000 miles of track had been laid in the Northern states and 9,500 miles in the South.