Help identifying a mini pennant
 

Anyone know what these are? I know there are other teams/cities, including minor leagues. I've had several BF3's and 1950 American Nuts, but I've never seen these before.

I have close to a full set of these but have no idea where they came from or when they were issued. I'm guessing the fifties but have no source. Recently they seem to be quite common on Ebay. There are five different leagues in the set.