It includes selected first-hand accounts, orders, reports, maps, diagrams, and correspondence drawn from official records of both Union and Confederate armies.
Collection of the records began in 1864; no special attention was paid to Confederate records until just after the capture of Richmond, Virginia, in 1865, when with the help of Confederate Gen. Samuel Cooper, Union Army Chief of Staff Maj. Gen. Henry W. Halleck began the task of collecting and preserving such archives of the Confederacy as had survived the war.
[5] In 1966, the U.S. National Archives began publication of a five-volume set that comprised an arguably superior index to the Army ORs, Military Operations of the Civil War: A Guide Index to the Official Records of the Union and Confederate Armies, 1861-1865, microfilm publication M1026.
They may not have been sophisticated about scholarly requirements for the reproduction of historical documents in print, but they were aware of the sort of problems involved and dealt with them according to shop practice, rich experience, and commonsense.
The sheer bulk of the material involved prevented any meticulous wholesale review of the copying process by the editors responsible for the eventual publication.
They were generally printers' errors, however, resulting from carelessness, difficulty in reading the manuscript, ignorance of proper names, and the like.
The numerous appendixes of material that did not get into its proper place, and the extent of the five supplemental volumes can give us some idea of how demanding and distracting this task must have been.