I'm not convinced that Mary was born in Germany; she may have been born in/near Philadelphia. The source says that Eli Bangs "m. about 1832 Mary Schuck, dau. of a German schoolmaster and music teacher, a native of Hesse Cassel, Ger." A lot of people have interpreted it to mean that Mary herself was from Germany, but I think it could also be interpreted as saying that her father was from Germany, but not necessarily that Mary was. So maybe one approach would be to look for a Schuck in Philadelphia in the early/mid 1800s who's a music teacher. I'm not sure how to go about that, other than slogging through city directories.