Suggest you contact the historian at the temple in Brookline, Ohabei Shalom (founded 1842) and the Judaica collection reference librarian at Brandeis University's Goldfarb Library. Numerous U.S. Jewish population estimates in cities, states, and regions have been made over time and published. (e.g. American Jewish Year Book). Market researchers can find that demographic slice. Pew Research found me 2 years ago for a survey.

Unlike Europe, the U.S. census does not contain a question about religion.

Pat Weinthal
Boston, MA