Researching MRS at the National Archives

National archives :
U.S. Army Chief of Transportation "Historical Program Files"
World War II historians should also take note of the records of the U.S. Army's Office of the Chief of Transportation (OCT), "Historical Program Files, 1940 50," which contain documentation of the role of the U.S. Army in the rail transportation system in the United States and information concerning foreign railroads during World War II. These files include records relating to army operation of all or parts of the U.S. railroad system in 1943, 1946, and 1950. A long report entitled Plan for the Possession, Control, and Operation of the Railroads by the Army, dated December 27, 1943, describes the army plan, mandated by executive order, to seize control of the nation's railroads in response to the threat of rail union strikes set to commence on December 30, 1943. The purpose of the plan was to ensure uninterrupted rail service in moving troops, war material, and equipment for the war effort. Army control of the railroads, assumed on December 27, 1943, was terminated on January 18, 1944, as the threat of strikes ceased.(21)
Other records in this file include historical reports of the Military Railway Service and the Transportation Corps, Rail Division; army technical manuals, plans, and regulations on hospital railway cars, railway kitchen cars, other troop cars, locomotive repair shops, and locomotive inspections; army field manuals concerning the Military Railway Service and the Railway Operating Battalions; copies of The Yankee Boomer, a newsletter of the Military Railway Service; reports concerning wartime traffic control and the relationships between OCT and the Interstate Commerce Commission and the Office of Defense Transportation; records of the American Association of Railroads including the scripts of The Line Behind the Lines -- The Story of Railroads in War, a series of ten weekly radio programs; correspondence concerning civilian labor recruiting due to manpower shortages; and a report entitled American Rails in Eight Countries: The Story of 1st Military Railway Service, which tells the story of supply and service in Europe during the war.
The Southern Railway System wrote a report called Well Done, which describes the efforts of Southern to teach the fine art of railroading to American soldiers who would be operating military railroads overseas. Southern trained the 727th Railway Operating Battalion and other units a total of six thousand officers and men. Also included in these records are the annual reports of the Pullman Company for the years 1942-1945 and the Railroad Retirement Board, 1942-1945.(22)
The U.S. Army Military Railway Service prepared reports on foreign railroads in Europe and Africa, including Tunisia, Algeria, Morocco, Iraq, Iran, Egypt, Libya, France, Belgium, the Netherlands, Spain, and Portugal. These reports include photographs, maps, charts, and general information concerning the status of foreign railroads in 1942-1943.(23) 

1st MRS Headquarters - Murphy

Railway Signaling and Communications, Volume 38 1945