The St. Marys & Kingsland, incorporated in 1906, completed the tracks between its two namesake Camden County towns soon thereafter. At Kingsland the railroad connected with the Seaboard Air Line Railway, while the other end at St. Marys provided coastal shipping opportunities.
In March 1911, the line was reorganized as the Atlantic, Waycross & Northern Railroad with plans to build well beyond Kingsland to the northwest. Various destinations including Abbeville, Unadilla, and Fort Valley were contemplated, but no extension was never constructed. In 1924 the line was reorganized as the St. Marys Railroad.