Brunk lists a half dozen or so BOWMAN c/s's. Sadly, you have only the last name. There are a few that read: BOWMAN / PHOTOGRAPHER / OTTAWA, ILL. Counterstamped coins that show a city, occupation and/or other identifying info are prized by collectors. Your friend's quarter may or may not be connected to this photographer. Consider that Bowman is not a particularly uncommon name.
It was not uncommon for 19th century folks to have a family name ENGRAVED on coins, called love tokens. On the other hand, counterstamped coins, having names punched from prepared dies, had some sort of mercantile connection. It's been estimated that more than 10% of the coins circulating in the mid-1800's were then counterstamped. These pocket change conversation pieces promoted word-of-mouth advertising at a time when a large portion of the population was illiterate and newspapers ads were a relatively limited medium.
In addition to photographers, a.k.a. artists, countless other merchants/professionals/inventors counterstamped coins. There were dentists, gunsmiths, silversmiths, jewelers, patent medicine sellers, entertainment venues, etc., etc. that c/s'd coins. Oftentimes, the denomination of the coin stamped was the price of admission, a hald dollar, or the cost of a drink, two-bits. Some c/s'd coins were used as checks, to redeem something. To me, it's a fascinating area of numismatic study that is growing in popularity and has yet to be more understood by coin collectors in general. One of the priciest coins ever sold was a counterstamped coin ... the Brasher Doubloon. Sadly, the "
RedBook" offers coin collectors no insight into other c/s issues and usage. Perhaps, the handiest and most affordable books for collectors to acquire are those written by Russell Rulau on 19th century tokens. Early editions can be nominally purchased and provide a wealth of info. One good find will more than pay for such a book!