Florida Gulf & Atlantic Railroad

The main line dates back to the mid-1800s. The line from Baldwin to Chattahoochee was first built as the Florida, Atlantic and Gulf Central Railroad from Lake City to Jacksonville in 1857. The Pensacola and Georgia Railroad built the line between Quincy and Lake City which was completed by 1863. The line would then be extended east to Chattahoochee to connect with the Pensacola and Atlantic Railroad.

In 1882, the lines were acquired by Sir Edward Reed, and were renamed together as the Florida Central and Western Railroad. Two years later, Reed brought the Florida Central and Western and several other Florida railroads he had purchased under the umbrella of what was named the Florida Railway and Navigation Company, which, in 1888, was renamed the Florida Central and Peninsular Railroad (FC&P). In 1900, a year after purchasing the majority of FC&P stock, the newly organized Seaboard Air Line Railway (a predecessor of CSX Transportation) leased the FC&P and, in 1903, acquired it outright.[4] CSX previously operated this segment as their Tallahassee Subdivision.

The main line continues west from Chattahoochee to Pensacola, Florida. This segment of the main line was originally built in 1881-1883 by the Louisville and Nashville Railroad, operating it as a subsidiary, the Pensacola and Atlantic Railroad. William D. Chipley and Frederick R. De Funiak (General Manager of the L&N), both of whom are commemorated in the names of towns later built along the P&A line (Chipley and DeFuniak Springs), were among the founding officers of the P&A. The line was merged into the L&N in 1891. In 1982, the L&N was merged into the Seaboard Coast Line Railroad, which in 1986 became part of CSX Transportation, operating this segment as its P&A Subdivision (a reference to the Pensacola and Atlantic Railroad).

The Bainbridge Branch runs from the FG&A Mainline in Tallahassee north to Attapulgus, Georgia, where it connects to CSX's Bainbridge Subdivision, which continues north to Bainbridge, Georgia. The Bainbridge Subdivision was first built in 1901 by the Georgia Pine Railway. The line was only intended to be a shortline for logging, but since it provided an additional rail route from Georgia into Florida, traffic increased. As a result, the line was renamed the Georgia, Florida and Alabama Railway by the end of 1901. The GF&A Railway bought the Carrabelle, Tallahassee and Georgia Railroad in 1906, which ran from Tallahassee south to Carrabelle.[5]

The Georgia, Florida and Alabama Railway, which extended from Richland, Georgia, to Carrabelle, Florida, at its greatest extent, became part of the Seaboard Air Line Railroad in 1927.[6] The Seaboard lines, after various other mergers, became part of CSX Transportation in 1986.

This line was previously part of CSX's Bainbridge Subdivision. The line's milepost numbers begin in Tallahassee at 52 and increase from there. This is due to the fact that the numbering still reflects the line's full length to Carrabelle, which was mile 0 before the track between there and Tallahassee was abandoned.[7]