Theater picture

I found this 8 by 10 inch picture in a drawer of the house we bought. . I have been asking around my small town. And i had heard theater was very big here. Im not sure the age. Possibly 1920 is my guess. And there was lots of big strikes going on around then. These men all have picket signs. Only one i can read says " Dont be a scab and strike one big Onion!" Which probably was union reference. The glass is old poured glass. And the back is sealed paper attached to the frame. Any thoughts would be great! Thanks for looking!