How to Decode a WWII US Army Serial Number

How to Decode a WWII US Army Serial Number

Gerald Ridenour, an Aviation Cadet in the U.S. Army Air Force, died in World War II. He was just shy of his 21st birthday. When my mom showed me his grave at Highland Cemetery in Perry County, Ohio, I knew I had to find out more about him.

The Casualty List

I found him listed on the WWII Army and Army Air Force Casualty List on Fold3. The information includes name, serial number, rank, and something pertaining to the death.

From World War II Honor List of Dead and Missing: State of Ohio. Online at Fold3 (titled WWII Army and Army Air Force Casualty List).

It was when I looked for the meaning of “DNB” that I discovered there is meaning in the serial number, also referred to as a service number.

WWII US Army Serial Numbers: Meaning in the First Digits

The U.S. Army began issuing serial numbers to help avoid mixing the records of people with the same name. (A genealogist’s dream come true!)  When we dig a little deeper into the number itself, we can learn a bit about the person.

Look at the First Number or Letter

Some prefixes were used in World War I. However, the following system began shortly before World War II. The first character gives us a lot of information.

• 1 = Enlisted in the Army (in other words, volunteered rather than drafted)
• 2 = Federally recognized National Guard
• 3 = Drafted
• 4 = Drafted
• O (that’s the letter O, not a zero) = Male commissioned officers
• W = Male Warrant officers
• T = Flight officers (Army Air Force)
• L = Commissioned officers of the Women’s Army Corps (WAC)
• V = WAC Warrant officers
• A = WAC enlisted women
• R = Hospital dietitians

• M = Physical therapy aides
  Looking back at the casualty list, we now know:

• Gerald Ridenour enlisted
• Arthur Porter was in a federally recognized National Guard unit
• Robert Pratt and Wilfred Ratliff were drafted
• William Petruzzi was a commissioned officer. (We also knew that from him being listed as a 2 Lt. But if his rank hadn’t been listed, we would have discovered he was a commissioned officer based on his serial number.)
  Look at the Second Number
  When you have an 8-digit serial number, the second number shows the Service Command. This narrows down where the person enlisted or was drafted. If you have a serial number for a member of the WAC, look at the number after the letter prefix. There’s an exception. Remember those serial numbers that begin with “2,” showing National Guard service? You need to look at the 3rd digit. (The second digit for those will always be a zero. You knew there’d be some exception, didn’t you.)

• 1 = Connecticut Maine, Massachusetts, New Hampshire, Rhode Island, Vermont
• 2 = Delaware, New Jersey, New York
• 3 = Maryland, Pennsylvania, Virginia
• 4 = Alabama, Florida, Georgia Mississippi, North Carolina, South Carolina, Tennessee
• 5 = Indiana, Kentucky, Ohio, West Virginia
• 6 = Illinois, Michigan, Wisconsin
• 7 = Colorado, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota, Wyoming
• 8 = Arkansas, Louisiana, New Mexico, Oklahoma, Texas
• 9 = Alaska, Arizona, California, Idaho, Montana, Nevada, Oregon, Utah, Washington
• 0 = When the first number is 3, the zero means he was drafted outside the U.S. (301 indicates Panama; 302 indicates Puerto Rico)

Since the second digit of Gerald Ridenour’s serial number is 5, we now know that he enlisted from either Indiana, Kentucky, Ohio, or West Virginia. The same for where Robert Pratt and William Ratliff were drafted. Arthur Porter, from the National Guard, also enlisted from one of those four states, since the third number of his serial number is 5.

A Note About Twins

According to the introduction to the World War II Honor List of Dead and Missing:

“Serial numbers are assigned with great care and according to a set of regulations. Consecutive serial numbers, for example, are not assigned to twins since this might cause confusion of identity between two persons with the same birth date and same general physical characteristics.”

Other Resources

• Jennifer Holik, Stories from the World War II Battlefield: Reconstructing Army, Air Corps, and National Guard Service (Vol. 1),  (Generations, 2015). Jennifer has put together a tremendous resource for researching members of the Army, Air Corps and National Guard from WWII. [NOTE: This is an Amazon affiliate link.]
• “US Army WWII Dog Tags” by Alain Batens on World War II Living History & Reenacting Information has great info about different styles of WWII dog tags and how to decipher them.
• The US Army Serial Number Generator at Hero Files will generate an accurate WWII-era Army serial number based on the criteria you enter. Useful for authors and reenactors.

References

• War Department, World War II Honor List of Dead and Missing: State of Ohio, (Washington, DC: by the War Dept., June 1946), p. ii. Available on Fold3.
• “Service number (United States Army)” on Wikipedia.
• “US Army WWII Dog Tags” by Alain Batens on World War II Living History & Reenacting Information.