Service numbers were used by the United States Army from 1918 until 1969. Prior to this, the Army relied on muster rolls as a means of indexing enlisted service members while officers were usually listed on yearly rolls maintained by the United States War Department. In the nineteenth century, the Army also used pay records as a primary means of identifying service members after discharge.
World War I
The Army first began using service numbers (SNs) in 1918 as a result of the United States' involvement in World War I and the need for a record tracking system capable of indexing the millions of soldiers who were joining the ranks of the National Army. Prior to this time, the only way to index lists of soldiers was by use of their legal names on rosters and muster rolls. As the strength of the National Army rose into the millions, this old method of muster rolls and rosters became outdated and a new system had to be developed.
The decision to create service numbers was made in February 1918, with the first service numbers to be issued only to Army enlisted personnel; the Army officer corps was still relatively small, and the U.S. Navy still maintained ships' rosters to keep track of its personnel. The U.S. Marine Corps and U.S. Coast Guard were also relatively small, and likewise without the need for a service number system to track personnel.
Enlisted men
The first soldier to receive an Army service number was Master Sergeant Arthur Crean, who received service number "1" in February 1918.Archival reconstruction record of Arthur B. Crean, Military Personnel Records Center, St. Louis, Missouri Throughout the remainder of World War I, service numbers were issued both newly and retroactively to most enlisted personnel with the numbers eventually ranging from 1 to 5 999 999.
Interwar period
Enlisted men
Enlisted service numbers continued where the World War I numbers had left off. Between 1919 and mid-1940, they ranged from 6 000 000 to 7 099 999. Enlisted personnel who were World War I veterans continued to hold their pre-6 million series service numbers. In 1920, the Army introduced the first service number prefix, which was a letter placed in front of the service number to provide additional information about the soldier. The prefix R identified personnel who had reenlisted into the Regular Army after the end of the war and the disbandment of the National Army. Arthur Crean was also the first person to receive a service number prefix, and his new service number became R-1. The Army also created an F prefix for those who had served as World War I field clerks.
Officers
In 1920, the Army began issuing service numbers to officers. The first officer service number was given to John J. Pershing, who held service number 1 with the prefix O, making his service number O-1.Military service record of John Pershing, Military Personnel Records Center, St. Louis, Missouri
Officers' serial numbers were generally determined simply by seniority and entry date into the Army officer corps; between 1921 and 1935, Regular Army officer numbers ranged from 1 to 19 999, with United States Military Academy (West Point) graduates in the 1920s and 1930s receiving numbers in the 20 000 to 50 000 range. Officers of the Organized Reserve and National Guard received numbers in an arbitrary but generally-increasing manner in the range of 140 000 or higher, and in 1935, the Army extended this sequence to 499 999. In 1935, the Army also created a second officer prefix, AO, intended for Regular Army officers who were aviators in the Army Air Corps.
World War II
By 1940, it was obvious to most in the U.S. military establishment that America might soon be involved in a major war. To that end, conscription was introduced in fall 1940 and the Army of the United States was activated as an augmentation force to serve in the coming war in a similar manner to the World War I National Army.
Enlisted men
In anticipation of a vast number of personnel again entering the Army ranks, a major expansion to the service number system was instituted in mid-1940. Originally, it was intended to simply continue the service number sequence, with new numbers starting at 8 000 000. The Army, however, chose to start a new number series at 10 000 000, with the eight and nine million-series being reserved for special uses; eight million series service numbers would later be used strictly by female Army personnel, while the nine million series service numbers were never issued.
Service numbers for Regular Army and Army of the United States voluntary enlistees began at 10 000 000 and extended to 19 999 999. The 11 000 000 through 19 999 999 series was issued to enlisted personnel who had enlisted within the boundaries of the 48 contiguous states and the territory of Alaska after 1 July 1940. The second number was determined by what corps area a person entered service from, while the next six identified the individual; thus, for each geographical area there was an available range of 999,999 service numbers. A subset of this series was reserved solely for enlistees from recruiting stations outside of the 48 contiguous U.S. states. The first number after the "ten" indicated the geographical region from which a person had enlisted, with the remaining numbers as a personal identification number. The geographical codes were 10 1 (for Hawaii Territory), 10 2 (for the Panama Canal Zone), 10 3 (for the Philippines) and 10 4 (for Puerto Rico). The remaining number codes (5, 6, 7, 8, 9, and 0) were unassigned and used by various recruiting stations outside the United States, including for men serving in the armed forces of allied nations who were formally transferred into the United States Army.
The geographical number codes were as follows:
Code State11Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont12Delaware, New Jersey, New York13Maryland, Pennsylvania, Virginia, Washington, D.C.14Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina, Tennessee15Indiana, Kentucky, Ohio, West Virginia16Illinois, Michigan, Wisconsin17Colorado, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota, Wyoming18Arkansas, Louisiana, New Mexico, Oklahoma, Texas19Alaska, Arizona, California, Idaho, Montana, Nevada, Oregon, Utah, Washington
Beginning in Fall 1940 and continuing until Fall 1941, the Army federalized the National Guard to augment the growing Army of the United States. Previously, there was no established procedure to issue service numbers to National Guard enlisted men in state service, since the vast majority had served solely under the authority of their state governments. Federalized National Guardsmen were given service numbers in the 20 million range, with numbers ranging from 20 000 000 to 20 999 999. Guardsmen federalized from Hawaii were issued service numbers beginning with 20 01 while the 20 02 series was used by men from Puerto Rico. With the exceptions of Hawaii and Puerto Rico, the first three numbers corresponded to a person's corps area, and the last five were a personal identifier. The geographical codes were as follows:
Code State20 1Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont20 2Delaware, New Jersey, New York20 3Maryland, Pennsylvania, Virginia, Washington, D.C.20 4Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina, Tennessee20 5Indiana, Kentucky, Ohio, West Virginia20 6Illinois, Michigan, Wisconsin20 7Colorado, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota, Wyoming20 8Arkansas, Louisiana, New Mexico, Oklahoma, Texas20 9Alaska, Arizona, California, Idaho, Montana, Nevada, Oregon, Utah, Washington
Conscripts into the Army of the United States were issued service numbers in the 30 million range, ranging from 30 000 000 to 39 999 999. The second number again corresponded with the corps area where a person had entered service, and the last six were a personal identifier. The geographical codes were as follows:
Code State or territory30was reserved for those who had been drafted from outside the United States30 1(Hawaii)30 2(Panama Canal Zone)30 3(the Philippines)30 4(Puerto Rico)31Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont32Delaware, New Jersey, New York33Maryland, Pennsylvania, Virginia, Washington, D.C.34Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina, Tennessee35Indiana, Kentucky, Ohio, West Virginia36Illinois, Michigan, Wisconsin37Colorado, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota, Wyoming38Arkansas, Louisiana, New Mexico, Oklahoma, Texas39Alaska, Arizona, California, Idaho, Montana, Nevada, Oregon, Utah, Washington
The 30 code was reserved for those who had been drafted from outside the United States with the third number following the "30" determining the extra-US draft location; the codes established were 30 1 (Hawaii), 30 2 (Panama Canal Zone), 30 3 (the Philippines), and 30 4 (Puerto Rico).
In 1942, the Army expanded the enlisted conscript service numbers and created the forty million service number series (40 000 000 to 49 999 999). These numbers were to be used for persons drafted from corps areas that had exceeded their initially allotted 999,999 numbers. In all, the only forty million series numbers that were ever issued ranged from 42 000 000 to 46 999 999. The forty million series numbers were discontinued after World War II and never reused.
A final service number series of World War II was the ninety-million series (90 000 000 to 99 999 999) which was reserved for members of the Philippine Army who had been called up to serve in the ranks of the U.S. Army. These numbers were rarely issued and the ninety million series was permanently discontinued after World War II.
During World War II, the Army also expanded the service number prefixes in addition to the original three prefixes (R, F, and O) which had been created after World War I. In all, the following prefixes were used during World War II.
Code Used byAfemale members of the Women's Army CorpsFfield clerks during the First World WarKfemale reserve and specialist officers with service numbers 100 001 and higherLenlisted members of the Women's Army CorpsNfemale nurse officersOofficers of the Regular ArmyRenlisted personnel with service #s from 1 to 5 999 999 upon reenlistment of the ArmyTflight officers appointed from an enlisted statusVofficers of the Women's Army CorpsWwarrant officers of the Regular Army
Officers
In 1942, officer service numbers were extended again to 3 000 000. The service numbers 800 000 through 999 999 were reserved for officers with special duties, while higher service numbers were held by graduates of Officer Candidate Schools or those who had been directly commissioned from the enlisted ranks. The Army also discontinued the prefix O, establishing that all officer numbers would begin with a zero. For instance, an officer with the service number O-2 345 678 would have the number written in military records as 02 345 678.
After the war
In October 1945, the Army discontinued the prefix "R" and issued the prefix "RA" to all members of the Regular Army. At the same time, the Army added several other R series prefixes to deal with special enlisted situations. In all, the R prefix series was:
Code Used byRAenlisted personnel of the Regular Army RMenlisted personnel holding temporary appointments as warrant officers of the Regular Army ROenlisted personnel holding temporary reserve officer commissions of the Regular ArmyRPretired enlisted personnel recalled to active dutyRVfemale warrant officers granted reserve commissioned officer billetsRWmale warrant officers granted reserve commissioned officer billets