Its construction was interrupted by the American Civil War, and initially only ran from Macon to Cochran, Georgia.

The 5 ft (1,524 mm)[1] gauge line was completed and extended to the Georgia coast when it opened in its entirety in December 1869.

Construction of the line stimulated the lumber industry along its path, and the founding of new towns and counties.

In July 1865, Arthur Cochran died and was soon replaced by George H Hazelhurst, former chief engineer of the company.

On July 2, 1873, governor James Milton Smith, announced that the state of Georgia had seized the Macon and Brunswick Railroad for failure to pay interest on its bonds.

In September 1879, the Georgia General Assembly passed an act authorizing the lease or sale of the railroad.

The construction of the railroad had a great effect upon the political geography of the area of Georgia through which it passed.

In the History of Dodge County (1932), Mrs. Wilton Philip Cobb wrote about the founding of Eastman, Georgia: In 1869 the Macon and Brunswick railroad (now the Southern) was built.

[12]During that period of economic expansion, stimulated by the railroad, Ira Roe Foster, former Quartermaster General of Georgia, operated a saw mill in Dodge County.

In his book The New South Comes to Wiregrass Georgia 1860-1910 author Mark V. Wetherington states: "Ira R. Foster shipped lumber to Brunswick, where it was loaded onto timber schooners and transported to international markets like Liverpool, Rio de Janeiro, and Havana.