It must be a popular question, because Elvis is the only person mentioned by name in the whole FAQ. (The other questions are more like “What is the origin of the 21-gun salute?”)
The short answer on Elvis: Two years active, four in the reserves. He entered the U.S. Army at Memphis on March 24, 1958, was formally received at Fort Chaffee in Arkansas, then trained at Fort Hood in Texas until September of that year. He spent October 1958 until March 1960 in Germany as part of a tank battalion in the 3rd Armored Division.
Elvis left active duty in March of 1960 and was discharged from the Army
Reserve in March of 1964. (Just in time.)
While perusing the Army FAQ, we also learned that shrapnel was named for Gen. Henry Shrapnel of the British Army. That factoid is part of a very informative, if brutal, analysis of how shrapnel differs from shell fragments.
Well, it’s nice to have something named after you.