Back in 1903, The Jewish Historical Publishing Company compiled a book about the history of the Jews of Louisiana. It was full of information about Jewish communities around the state. Unfortunately, Monroe had only one page of information! The Internet Archives has digitized it and you can take a look at it here:
Great info on Rabbi Heinberg (spelled incorrectly as Heimberg!), Henry Bernstein (who would later become mayor) and Henry Meyer. The Jewish community was much bigger than that though. Such a shame Monroe got the short shrift!