The military dog tags we know had their origins during WWI (1914-1918). Before that soldiers used various ad hoc methods of tagging  themselves for purposes of identification in the event of death on the battlefield. The concept of "identification tags" dates back to the Civil War (1861-1865) where names were written on paper tags and pinned to clothing, dog tags were made out of wood with carved holes at the end so they could be worn around the neck on a string. The first introduction of a metal "identity disc" took place in 1906 and by 1913 the Army made ID tags mandatory. In 1916 a second tag was added and by 1917 all combat troops had aluminum ID tags hanging from their necks on either a rope or chain. The information on these tags were hand stamped with tool and die. Next came an oblong shape tag with more uniform printing known as the Navy/Marine style tag. The materials used to make this tag included brass and a "Monel" metal which provided more corrosion resistance. The History of Dog Tags - Part II will follow shortly.