Q From Bob Dahl: Where did the name long johns for the underwear come from. The long is easy, why johns?
A I was afraid somebody might ask me this, because it forces me to adopt that foot-shuffling, hang-dog posture that indicates to the discerning spectator that my reputation for omniscience has taken another tumble. We just don’t know for sure. However, I can salvage my standing with some new facts.
The boxer John L Sullivan.
The earliest references to the garments strongly suggest the name came to wide public attention because it was applied to the long underwear issued to American soldiers during World War Two. The first known reference to them used to be in a publication of 1943, but I’ve succeeded in taking that back a couple of years, to a letter home by a new recruit:
We have had but three days of rain in the nine weeks we have been here. Last Friday it turned a little cool so we were issued our winter clothes. We all hope we don’t get our ‘long Johns’ for a while because it is too warm yet.
Sheboygan Press, Wisconsin, 16 October 1941
Another local newspaper reference suggests an origin:
Many a rookie has been ridiculed and laughed at the first time he swallowed his pride and donned his LONG JOHNS. They are the winter underwear issued by the Army, and have the disturbing effect of making a G.I. look like a scarecrow trapeze artist. It might be added that they itch but good! After a soldier finally gets into his LONG JOHNS, he invariably swells his chest, flexes his biceps and struts around the barracks like a John L. Sullivan, after whom these practical if not sightly garments have been named.
Wisconsin Rapids Daily Tribune, 3 June 1944.
Do I believe this? The rule of thumb that 99% of such stories about the origins of expressions turn out to be rubbish suggests that I ought not. But this might just be the exception, since the classic pictures of the famous boxer show him wearing long white drawers or skivvies tucked into his socks. Stranger origins are known.