To hear it told in western movies or novels, every cowboy, marshal, and sheriff had a sidekick. Of course, some people wonder why only one of the pair was ever called a sidekick, and it does seem a bit unfair that the sidekick didn't have a sidekick. Be that as it may, why should such a person be called a sidekick? It certainly doesn't seem to be involved in aggressive footwork of any kind.
In fact, it seems to go back to the Old World, to London. At one time,
the city was rife with pickpockets; so prominent were they that light-fingered thieves
had their own apprentices, much as did blacksmiths or weavers. This brotherhood had its
own argot; the pockets to be picked were kicks. Now the most difficult pants'
pockets to relieve of their goods were the side ones, especially if the target was
walking. Keeping your money in the side pocket with your friend walking on that side
saved many a pocket from being plundered. And gave rise, so it's said, to the
sidekick.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.