The military historian who attempts to record the history of the European Theater of Operations is faced with an astounding amount of documentary materials. The After Action Reports and journals of the sixty-one American divisions in the ETO alone form a collection weighing some thirty-seven tons. The main problem for the historian, therefore, is not that of finding information, but of cutting down and compressing the materials at hand. Gaps in the records do occur, but as a rule these are the occasion for minor irritation rather than major concern. The records of all the higher headquarters, including SHAEF and the War Department, have been collected and opened to the historian. Here the practice of making multiple copies of even the most secret dispatches or orders insures against the possible disappearance of a significant original.
What the historian has gained by the widespread use of such mechanical aids as the typewriter, the teleprinter, and the mimeograph is partially offset by the ease with which commanders, traveling by jeep and liaison plane, now meet face to face for informal, unrecorded, but nonetheless decisive, discussion. The commands and decisions stemming from such meetings find their way into the written record, but the personal exchanges and the reasoning that culminates in the decision often are irretrievably lost to the historian, despite attempts through oral and written interrogation to plumb the memories of the commanders involved. It is doubtful whether the spate of memoir literature which we may expect at some later date will fill the lacunae acceptably.
Information on tactical units comes from three general sources: the unit journals, the After Action Reports required by Army Regulations, and interviews conducted by historical officers during and after battle. The unit journals, containing messages and orders, are an absolutely reliable guide to what was known at the time. Overlays showing troop dispositions, reports on patrols, intelligence estimates, and similar material are appended to these journals. The After Action Reports, compiled at the close of each month of operations, are based to a considerable extent on the unit journals but also contain information not normally recorded in the form of messages or orders. Errors will be found in the After Action Reports. The percentage of error increases in
progression up the echelon of command, since the army corps After Action Report tends to rely on that coming from the division, and the division normally uses the After Action Report prepared by its regiments. The After Action Report, however, is the most convenient guide through the maze of combat information and the historian can soon determine the quotient of reliability for the individual unit preparing it. Unit journals and After Action Reports prepared in the ETO are now in the possession of the Historical Records Section, Office of the Adjutant General.
During operations in Europe historical officers attached to the various armies interviewed officers and men who took part in or directed the fighting. More than two thousand of these Combat Interviews are on file in the Historical Division. Their coverage varies from the interrogation of one officer to that of an entire combat formation. Some interviews were obtained while the unit was in action; others were secured weeks after the action occurred. The hours and dates reported in the Combat Interviews are often in error, for these are things which the soldier, living in twelve-hour periods, quickly forgets. The Combat Interviews also reflect the extreme localization of knowledge that occurs on the battlefield and cannot be accepted as final evidence when reference is made to units supporting or adjacent to the formation from which the interview comes. This corpus of Combat Interviews, however, is one of the most valuable sources of information available to the historian. It fleshes out the framework of events chronicled in the unit journals and provides additional testimony to help resolve disputed questions of fact.
Information on the enemy comes from two general sources: War Diaries (KTB’s) and other German Army documents now in our possession; manuscript histories prepared after the war by German officers who played a part in the events they describe. The collection of German Army records (held by the German Military Documents Section, Office of the Adjutant General, for the United Kingdom and the United States) is by no means complete. Tons of such documents were destroyed by the Germans or by looters and vandals. Large collections of War Diaries, particularly in the Potsdam archives, went to the USSR and are not available to the Western historian. Nonetheless the enemy records extant and available suffice for the compilation of a reasonably complete and accurate account of the German armies that faced the Allies on the Western Front during the campaigns of 1944 and 1945. Enemy information derived from contemporary documents has been augmented by approximately one thousand manuscript histories written after the war by German
officers in Germany under the direction of Col. H. E. Potter, USA. This collection, to which additions on the later phases of the war in Europe are still being made, is in the possession of the Historical Division. Although these manuscript histories depend almost entirely on the unaided memories of their writers they add immeasurably to our knowledge of the enemy operations. When checked against German Army documents and Allied sources the manuscripts show an amazing degree of accuracy and objectivity (probably explained by the professionalism of the German officer corps, the academic traditions of the German General Staff, and the destruction of those German military institutions to which personal reputations have been attached).
The amount of information on operations in the ETO which has found its way into print since the end of the war is rather limited. A number of semiofficial histories prepared by corps, divisional, and regimental associations have been published in Germany and the United States. Such works vary greatly in value, but all those pertinent to the present volume have been examined. Thus far the only memoirs that refer in any detail to the Lorraine Campaign are those of General Eisenhower and General Patton. These two works have been used, but as a rule reference in the present volume is made to the original documents from which the memoirs derived their information.