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.

ridenour-casualty-list

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

References

How to Decode WWII US Army Serial Numbers World War II US Army serial numbers weren't random. This guide will show you what each part means.

Our Military Heritage

The Genealogy Center at the Allen County Public Library in Fort Wayne, Indiana has done it again. They’ve come up with another wonderful resource for genealogists: Our Military Heritage

Our Military Heritage has numerous digitized books that are full-text searchable. They range in subject from the Lucky Bag (the Naval Academy yearbook) for 1906 to The United States Navy in the World War (an awesome collection of photos from the War Department) and the Valley Forge Orderly Book of General George Weedon. One book I was particularly impressed with was Woman’s Work in the Civil War. It contains dozens of biographies of women who served as nurses, aid society organizers, etc. (I particularly liked the section titled “Ladies Distinguished for Service in Soldiers’ Homes and Volunteer Refreshment Saloons.” (Funny, I thought the latter were called “bars” 🙂 )

There are also original documents, such as the Civil War diary of Robert E. Best of the 36th Indiana Volunteer Infantry, letters of John C. Potts of the 95th Ohio Volunteer Infantry, and a World War II diary of George P. Martin, a purchasing agent in Brazil.

Most of the resources can be found in the Genealogy Center at the Allen County Public Library. (The website even gives the call number when it’s available.) They are encouraging people to submit their own material, too.

With materials ranging from the Colonial Wars to World War II (with material for the Korean War, Vietnam and, one would presume, more recent wars to be coming soon), there is something for everyone on Our Military Heritage. This is definitely a site worth keeping an eye on and checking often!

OhioWarStories.org

With the advent of Ken Burns’ new WWII documentary, The War, we are certain to see more and more projects to capture the memories of WWII veterans. When you consider that they are dying at the rate of approximately 1,000 per day, you realize how important it is that we talk to them now. Tomorrow may be too late…

One project is a collaborative effort of the PBS stations in Ohio. They have created a website – www.ohiowarstories.org – which features videos of interviews with veterans as well as civilians who assisted the war effort from the homefront. There are some truly powerful stories.

If you are a WWII vet or know one, record the stories now. Future generations should know what they did.