Military service records of volunteer soldiers, both Union and Confederate, were abstracted onto cards from muster and pay rolls, rank rolls, returns, hospital records, prison records, accounts for subsistence, and other records. The compiled records for Confederate soldiers usually have facts about a soldier's imprisonment. If a soldier was captured, the record may show the date of his release and parole (exchange for Union prisoner), or, if he died in prison, the date of death.

The card abstracts for each soldier were placed into a jacket-envelope bearing the soldier's name, rank, and military unit. The jacket-envelope, containing one or more abstracts and, in some cases, including one or more original documents relating specifically to one soldier, comprises the compiled military service record.

A compiled military service record is as complete as the records of an individual soldier or his unit. A typical record shows at least the soldier's rank, military unit, and dates of entry into service, discharge or separation by desertion, and death or dismissal. It may also show age, place of birth, and residence at enlistment. Many records include much more detail, including whether or not the soldier was present in particular military actions, AWOL, sick, wounded (often the nature of the wound is documented), etc.

The name on the jacket-envelope was chosen from one of the abstracts contained in the soldier's compiled military service record. It is not necessarily the correct name of the soldier, nor is it necessarily the way his name was most frequently spelled in the original records.

The rank shown at termination of a soldier's service may not be the highest rank he attained while in service.

If a soldier served in more than one unit, there may be more than one jacket-envelope for him, and his other service may not be cross-referenced in the record or on the jacket. Additional service by the same soldier rendered in a state militia unit that was never mustered into Confederate service is not documented in the records at the Archives.