Great list from Wikipedia page for the Military Railway Service units - 1st 2nd and 3rd MRS

Great list from Wikipedia page for the Military Railway Service units - 1st 2nd and 3rd MRS  
 

List of Railway Grand Divisions and their sponsors
Unit      Sponsor     Date of Activation
701st     New York Central Railroad     01/11/1943
702nd     Union Pacific Railroad     10/15/1942
703rd     Atlantic Coast Line Railroad     08/01/1943
704th     Great Northern Railway     11/30/1942
705th     Southern Pacific Lines     05/19/1943
706th     Pennsylvania Railroad     08/06/1943
707th     Southern Railway     06/10/1943
708th     Baltimore and Ohio Railroad     04/06/1943
709th     Association of American Railroads     03/15/1944
710th     Atchison, Topeka and Santa Fe Railway     12/14/1943
774th     None (Organized in Italy)     1944
 

List of Railway Operating Battalions
Unit     Sponsor     Date of Activation
711th     Training Battalion. Built and maintained the 50 mile Claiborne-Polk Military Railroad     05/01/1941
712th     Reading Railroad     10/25/1942
713th     Atchison, Topeka and Santa Fe Railway     04/15/1942
714th     Chicago, St. Paul, Minneapolis and Omaha Railway     10/31/1942
715th     Illinois Central Railroad     10/31/1942
716th     Southern Pacific Lines     12/21/1943
717th     Pennsylvania Railroad     12/01/1943
718th     Cleveland, Cincinnati, Chicago and St. Louis Railway     12/14/1943
719th     Texas and New Orleans Railroad     09/01/1943
720th     Chicago and North Western Railway     08/26/1943
721st     New York Central Railroad     04/14/1943
722nd     Seaboard Air Line Railroad     12/14/1943
723rd     Union Pacific Railroad     12/28/1943
724th     Pennsylvania Railroad     12/28/1943
725th     Chicago, Rock Island and Pacific Railroad     02/17/1943
726th     Wabash Railroad     06/26/1943
727th     Southern Railway     03/15/1942
728th     Louisville and Nashville Railroad     01/11/1943
729th     New York, New Haven and Hartford Railroad     01/11/1943
730th     Pennsylvania Railroad     05/15/1942
731st     Union Pacific Railroad     Did not Activate
732nd     Great Northern Railway     01/12/1944
733rd     Central of Georgia Railway     11/23/1943
734th     Texas and New Orleans Railroad     02/23/1944
735th     ARR/Erie Railroad     02/10/1944
736th     New York Central     Did not Activate
737th     New York Central     09/30/1944
738th     Chicago Great Western Railway     Did not Activate
739th     Lehigh Valley Railroad     Did not Activate
740th     Chesapeake and Ohio Railway     12/14/1943
741st     Gulf, Mobile and Ohio Railroad     01/12/1944
742nd     Pennsylvania Railroad     Did not Activate
743rd     Illinois Central Railroad     01/12/1944
744th     Chicago, Milwaukee, St. Paul and Pacific Railroad     12/21/1943
745th     Chicago, Burlington and Quincy Railroad     05/19/1943
746th     Missouri–Kansas–Texas Railroad     05/04/1944
747th     Atchison, Topeka and Santa Fe Railway     Did not Activate
748th     Texas and Pacific Railway     05/12/1943
749th     New York, New Haven and Hartford Railroad     02/23/1943
750th     St. Louis – San Francisco Railway     03/21/1944
751st     Denver and Rio Grande Western Railroad     Did not Activate
752nd     Boston and Maine Railroad     05/04/1944
759th     Missouri Pacific Railroad     09/01/1942
761st     Railway Transportation Company     07/22/1942
770th     None     08/09/1942
790th     None     07/08/1943
791st     No sponsorship (activated at Andimeshk, Iran)     07/01/1943
 

List of Railway Shop Battalions
Unit     Sponsor     Date of Activation
753d     Cleveland, Cincinnati, Chicago and St. Louis Railway     04/15/1942
754th     Southern Pacific Lines     10/25/1942
755th     Norfolk & Western Railway     11/30/1942
756th     Pennsylvania Railroad     01/11/1943
757th     Chicago, Milwaukee, St. Paul and Pacific Railroad     06/10/1943
758th     Atchison, Topeka & Santa Fe Railway     04/06/1943
760th     No sponsorship     06/16/1942
762d     No sponsorship     10/15/1942
763d     Delaware, Lackawanna and Western Railroad; Lehigh Valley Railroad     07/27/1943
764th     Boston & Maine Railroad     10/25/1943
765th     Erie Railroad     05/01/1944
766th     Association of American Railroads     07/17/1944

Note: The 760th and 762d were RSB (Diesel); all others were RSB (Steam).