The Buffalo Union-Carolina was apparently built in 1900 to deliver supplies for the construction of the textile mill in Buffalo, and then served the mill from an switch-back style interchange with the Southern Railway in Union. The railroad went through Union then paralleled or used trackage rights on the Southern from Monarch Mills to southeast of town. The railroad then diverged to Gregory, a power plant at Neal Shoals on the Broad River, and then down to Pride on the Seaboard Air Line just northeast of Carlisle. This section of the road was apparently built to serve the power plant along the river, and to provide a connection other than with the Southern. The section between Monarch Mills and Pride was abandoned between 1945 and 1959. The section between Union and Buffalo came into possession of Southern, and Southern abandoned it by 1971.

The former ROW can be made out in aerial photos in places between Monarch Mills and Neal Shoals, and some sections have been made into roads. The section between Union and Buffalo is still easily distinguishable. Some sections in Union may be able to be made out.

The pictures on this page were provided by Tim Mitchell of Union. His grandfather, Rueben Mitchell, was an engineer on the BU-C in the 1940s. After his retirement, the company let him come back and make the first diesel run on the line (probably in the 1950s).