a spur to Port Walthall (red) gave the Richmond and Petersburg Railroad (yellow) a way to compete with the Petersburg Railroad's connection to City Point (blue)
Source: Library of Virginia, Bacon's large print war map showing 50 miles round Washington and Richmond (1864)
The Richmond and Petersburg Railroad became embroiled in the competition for business at the ports of Richmond, Petersburg, and Norfolk/Portsmouth.
The Portsmouth and Roanoke Railroad started operating trains between Weldon, North Carolina and Portsmouth in 1837. That offered an alternative market for Roanoke River freight. Tobacco, timber products, and various agricultural products from Mecklenburg and other Southside Virginia counties had previously gone north to Petersburg via the Petersburg Railroad. Some went on to Richmond via the Richmond and Petersburg Railroad, with tobacco being processed there before shipment to final markets.
The Richmond and Petersburg Railroad initially partnered with the Petersburg Railroad to the south and the and the Richmond, Fredericksburg and Potomac Railroad to the north, to offer a joint fare for freight/passengers going to to Baltimore. The joint fare was lower than the Portsmouth and Roanoke Railroad fare, plus what customers had to pay a steamship company to get from Portsmouth to Baltimore.
The Portsmouth and Roanoke Railroad then partnered with the Bay Line, and that rail/steamship fare drew traffic back to Portsmouth. Profits were sacrificed in the process The price war ended after the Portsmouth and Roanoke Railroad went into bankruptcy in 1846.1
The Richmond and Petersburg Railroad upgraded the track to Port Walthall in 1840, after Petersbrg constructed a rail connection to City Point. Port Walthall was downstream from the wharves of Manchester and at the mouth of Gillies Creek. Ships sailing upriver could make a shorter trip to load/unload at Port Walthall, and it provided deeper water for larger ships.
the Richmond and Petersburg Railroad in 1856
Source: Library of Congress, Map of the Springfield & Deep Run estates on the Coal Lands of the N. York & Richmond Coal Co, in Henrico Co. Virginia (by S. Herries DeBow, 1856)
bridge of the Richmond and Petersburg Railroad crossing the James River, as rebuilt after the Civil War
Source: Picturesque America, Richmond From the James (Volume 1, 1872)
1. Peter C. Stewart, "Railroads and Urban Rivalries in Antebellum Eastern Virginia," The Virginia Magazine of History and Biography, Volume 81 Number 1 (January, 1973), p.7, http://www.jstor.org/stable/4247766 (last checked August 10, 2016)