Built at the end of the 19th century in 1899, this line was part of the original Jacksonville and Southwestern Railroad mainline between Jacksonville and Newberry to the southwest. The main intent of the line was to tap into the phosphate-rich regions around Newberry and transport the raw materials to a mill in Jacksonville. The J&SW was purchased by the Atlantic Coast Line railroad on July 28, 1904 and subsequently merged into the ACL system. The portion of the line between Langmar and Hainesworth was abandoned in 1968 while under the ownership of the Seaboard Coast Line Railroad.
Towns along the line, west and south from Langmar: Baldwin, Mattox, Sapp, Ralford, Lake Butler and into Hainesworth, just outside of Alachua. At Langmar, the abandonment ends at a connection with the CSX Callahan Sub; from there, the line is active and continues eastward to Jacksonville. At the other end of the abandonment, in Hainesworth, the CSX Brooker Sub (ex-SCL, ex-ACL) joins with the abandoned right-of-way and continues southward to Newberry.
Portions of the abandoned right-of-way are still visible along FL Route 121 for about 10 miles southeast of Baldwin. The portion of the line between Langmar and Baldwin is paved rail-trail.
Thanks to Jonathan W. Filion for contributing information about this route.