The United States Military Railroad Construction Corps (USMRRC) was instrumental in Grant's plan to defeat Lee's Army of Northern Virginia during the Siege of Petersburg. From the waterfront at City Point Grant supplied more than 100,000 troops and more than 65,000 horses mules. Living off the land was not an option. All food, equipment and supplies had to be shipped in from northern ports and then delivered to the battlefront eight miles from City Point.
Eight wharves were built to accommodate hundreds of vessels conveying war material. More than 280 buildings were constructed by the USMRCC at City Point by the end of the siege. The lumber was pre-cut as per orders and then assembled once it arrived. The sleepy little village took on the appearance of a thriving, bustling port in just a few days.
As the siege progressed Grant extended his lines around Petersburg and the United States Military Railroad (USMRR) followed. After every major action, with few exceptions, the railroaders received orders to investigate the terrain and chose a site suitable for a temporary rail line. In the nine months of the siege 21 miles would be laid, 25 locomotives and more than 275 rolling stock would be used, and 2,300,000 miles would be logged on the railroad. Thousands of troops used the line but the primary cargo was food, weapons, and ammunition. Wounded soldiers were eventually transported by rail to the Depot Field Hospital at City Point.
Stations were established along the railroad for distribution of supplies. Sidings were built at these stations so trains unloading would not interfere with other trains on the line. On average eighteen trains made the trip from City Point to the front and back again and timetables were published to insure smooth running.
The ultimate Union victory over the Confederate army of Lee at Petersburg is due in part to the well organized operations of the USMRCC. The transportation system and the logistical apparatus established by the Federals during the Siege of Petersburg enhanced Grant's ability to ensure the collapse and final defeat of the Confederacy in Virginia.