From Panama Park, the Kingsland Subdivision heads north to Yulee on a discontinuous piece of CSX's S Line.
In Yulee, the line connects with the First Coast Railroad, which operates north to Seals, Georgia, on tracks that were previously part of the Kingsland Subdivision prior to 2005.
The line's namesake is Kingsland, Georgia, which is located north of Yulee on the First Coast Railroad.
[4] From Panama Park north, the line was built by the Fernandina and Jacksonville Railroad, which was organized in 1874 and opened in 1881.
The original Seaboard Air Line track from Panama Park south to Jacksonville is now the S-Line Urban Greenway.