In order to understand how the numbered record books came to be the distinct body of records they presently constitute in the War Department Collection of Revolutionary War Records, it is necessary to understand the composition and organization of the entire Collection in terms of its major components.
Many of the Revolutionary War records acquired by the War Department were placed in one or the other of two large files of unbound material. Muster rolls, returns, pay lists, guard reports, and other records showing the military service of persons in particular organizations were placed in one of these files (reproduced as Revolutionary War Rolls, 1775-83, M246). Letters, receipts for pay, supply returns, and other records of a miscellaneous character were placed in the second file generally referred to as the "Manuscript File" (reproduced as Miscellaneous Numbered Records (The Manuscript File) in the War Department Collection of Revolutionary War Records, 1775-1790's, M859).
Some bound records were taken apart and their contents added to these files. The photographic copies of records made in 1914-15 were kept together as a third major record aggregation. "Compiled military service records" were created mainly from the information in the records composing the file of rolls, returns, and related items.
To index these compiled records—which consist of one or more paper jackets for each person whose name appears in the rolls and returns file, with one or more cards in each jacket containing information copied from the original records, a "General Index" was prepared (reproduced as General Index to Compiled Military Service Records of Revolutionary War Soldiers, M860). Another name index, the "Special Index" (reproduced as Special Index to Numbered Records in the War Department Collection of Revolutionary War Records, 1775-1783, M847), was prepared for the "Manuscript File."