The correct answer is B) move more men and supplies.
The North’s control of railroads gave it an advantage during the Civil War because it could move more men and supplies.
During the American Civil War, Railroads played an important factor in the transportation of soldiers and supplies. In the northern states, there were approximately 22,000 miles of roads, compared to the 9,000 in the South. IT still amuses historians that the confederacy did not pay much attention to the control of railroads, as the Union Army did. For the Union, it was very important to control the key southern railroad stations such as Richmond, Atlanta, and Chatanooga.