The Birnbaum family business?

I'm embarassed to admit this, but I don't know what my grandparents and earlier generations did for a living. How long had our branch of the Birnbaums live in Roswadov, and was there a family trade or craft that went down the generations??
My father told me thet Avrum was a highly respected man in the town, something like a mayor. Does anyone know about this, and was this position just among the Jewish community there?
When did the exodus from Poland begin? Was Leo the first to leave Poland? It's interesting how spread out Tobe and Avrum's children were, some in Toronto, some in New York and some in Israel. Of course the most haunting and distressing aspect of the family history is that Avrum, Tobe and Ruchel went back to Poland on the evev of WW2 and were killed in the Shoa. I still find it hard to get my head around the fact that they did go back at such a late date (1939 is the date I was told). It's such a terrible tragedy that they got out but went back into that inferno.