As near as I can tell from reading, Bettas have been bred by hobbyist
     for at least 140 years, Though somewhere around 1900 to 1930 they were
     being talked about among fish breeders and hobbyist here in the US.
     Recently there has been an increased popularity of them in pet stores.
     I think the Internet has helped to make more people aware of them 
     as an easy pet to take care of.