the Atlantic Coast Line had two stretches of track in Virginia in 1905, including the former Norfolk & Carolina Railroad from Pinners Point
Source: Annual Report of the State Corporation Commission of Virginia - Volume 2 (1905), Chesapeake Western Railway (p.11)
After the Civil War, Virginia-based owners of railroad stocks and bonds lost control as corporations went bankrupt. The Virginia-based owners came from regions that competed for trade, and invested in railroads in order to transport freight from the interior "hinterland" to rival cities.
Business and political leaders in the ports of Alexandria, Fredericksburg, Richmond, Petersburg, and Norfolk were not interested building railroads that were just profitable businesses. They funded rival transportation networks to steer trade away from one port and towards another. Financing the most cost-effective expansion of railroads was a much lower priority.
Financiers from the northern states and England were focused the profitability of railroads, no matter what port was served by the lines. The Atlantic Coast Line was assembled from several major rail lines that were separate before the Civil War. Starting in 1871, new owners synchronized their operations and rates in order to increase traffic and profits together. Lines in Virginia included the Richmond & Petersburg Railroad and the Petersburg Railroad between the James River and the North Carolina border, and the Norfolk & Carolina Railroad between the Elizabeth River and the North Carolina border.
The unification of the separate lines was formalized with the incorporation of the Atlantic Coast Line in 1900. Two North Carolina railroads started to use "Atlantic Coast Line" as a marketing tool since 1871. The different laws in different states, plus the challenge of finding the necessary funds to buy the stock and gain control of other railroads, complicated consoldation of different companies.
The Atlantic Coast Line partnered with the Louisville & Nashville Railroad to lease the Carolina, Clinchfield & Ohio Railroad in 1925. That streamlined the process of hauling West Virginia/Virginia coal to textile mills and to the South Carolina port of Charleston.1
Much of the Atlantic Coast Line traffic ran from Virginia to Florida, in competition with the Seaboard Air Line. The two lines ran in parallel from Richmond to Florida, with common service to 121 locations.
The two companies agreed to merge in 1960, to reduce operating costs. Construction of the interstate highways required streamlining railroad operations to compete with trucks for freight traffic and with cars for passenger traffic.
After seven years of legal fights, the merger was implemented in 1967 to create the Seaboard Coast Line. That railroad integrated operations with other lines in the Sutheastern United States to create "The Family Lines."2
In 1986, the new CSX Transportation Company absorbed the Seaboard Coast Line, ending its separate existence.
the Atlantic Coast Line competed with the Seaboard Air Line and the Piedmont Air Line
Source: Atlanta Illustrated (1881, p.243)
1. "Atlantic Coast Line, Standard Railroad of the South," American-Rails.com, https://www.american-rails.com/atlantic-coast-line.html; "North Carolina Railroads - Norfolk & Carolina Railroad," Carolana, http://www.carolana.com/NC/Transportation/railroads/nc_rrs_norfolk_carolina.html; George A. Kennedy, "Atlantic Coast Line Railroad," NCpedia, 2006, https://www.ncpedia.org/atlantic-coast-line-railroad; "Atlantic Coast Line Railroad," RailGA.com, http://www.railga.com/acl.html (last checked December 27, 2018)
2. Mike Schafer, Classic American Railroads, Volume 3, MBI Publishing Company, 2003, p.17, https://books.google.com/books?id=MCxgsaXmILcC (last checked December 26, 2018)