A brief history of the dog tag

Armies have always had a need to track and identify soldiers. As far back as the American Civil War, soldiers began wearing metal or wood discs, and jewelry that bore their name and identifying information. But this practice was not standardized and not mandatory. This resulted in a staggering amount of those killed in the Civil War being unidentified. Amazing by today’s standards of DNA identification, of the 17,000 Civil War dead buried in Vicksburg National Cemetery, some 13,000 remain “known but to God.”

It wasn’t until the turn of the 20th century that the U.S. military made the wearing of identification tags mandatory. The Army used a circular shaped disc made of aluminum. Imprinted by hand, they contained the soldier’s name, service number, rank, unit and branch of service. Two were issued and worn around the neck on a cloth cord or chain. In the event of a casualty, one would always stay with the body, while the other would be retained by the fallen soldier’s unit. By the time the U.S. Army entered WWI, all troops were wearing the aluminum identification tags.

The Navy used an oval-shaped disk made of monel, an alloy of nickel and copper, melted together with iron and magnesium. Instead of stamping, they used a nitric acid formula to etch the information onto the disc. They also etched the owner’s fingerprint onto the disc as an additional means of identification. This is also seen on Marine Corps ID tags up until about 1940 to 1941. As WWII erupted, hand stamping and acid etching proved too time consuming to process the millions of people entering the military.

In 1940, the Army started issuing a “notched” rectangular identification tag with rounded edges. These were machine stamped and contained all the vital information necessary to identify the wearer. Initially, they included the soldier’s home address, so next of kin could be notified. But this practice was soon dropped for security reasons. The notch led to a long-standing story that it was designed to be wedged between the teeth of the deceased soldier. Nothing could be further from the truth! The notch was there to hold the tag in place, in the machine, which imprinted the wearer’s information. By the 1950s, all branches adopted the Army’s rectangular identification tag, new stamping machines no longer required the notch, and the same basic design is still in use today.

So how exactly did the term “dog tag” get coined? While no one is 100% certain, it seems to center around WWII draftees, who felt they were treated like dogs and wore their “dog tags” around their necks, on a chain, just as dogs wore theirs around their neck on a collar.