The Meridian & Bigbee Railroad Company was the reorganized name for the Meridian & Bigbee River Railway, originally incorporated in 1917. By 1928 the River shortline had built east from Meridian, Mississippi, across the state line eastward to Cromwell, Alabama, and was later completed to Myrtlewood by 1935. In 1933, a trustee was appointed to manage the line, and it was not until 1942 that the company was reorganized under its more familiar name. In the diesel era, the 51-mile shortline was owned by the James River Corporation and moved pulp, chemicals, and paper products. Enginehouse was at Meridian.

Currently owned by the Genesee & Wyoming shortline system, who purchased it in 2005, the line has been reorganized as the M&B Railroad, with reporting marks MNBR. The current shortline stretches 168 miles through Linden and Selma, Alabama, as far east as Burkville, with trackage rights into Montgomery. The eastern end of this longer shortline is former Louisville & Nashville trackage purchased by G&W. The line now carries aggregates, agricultural products, chemicals, forest products, pulp and paper, metallic ores, and mineral products. Several points of interchange are mainted: with Alabama & Gulf Coast Railway (Linden, Al); with Burlington Northern Sante Fe (Linden, Al); with CSX Transportation (Montgomery, Al); with Kansas City Southern (Meridian, Ms); with Norfolk Southern (Meridian, Ms and Selma, Al).