On October 3, 1846, in the dry-goods emporium of Rosenfeld and Rosenberg, 15 Jews founded the first Jewish congregation in the city, Kehillath Anshe Ma'arav ("the Congregation of the People of the West"), subsequently referred to as KAM. They practiced the traditional Minhag Ashkenaz and worshiped in a room above a clothing store. The Jewish Burial Ground Society merged with KAM, and KAM dedicated the first Chicago synagogue in 1851. 

http://kamii.org/category/categories/our-history-and-mission