To know the Catholic Church to which your Immigrant ancestors would have belonged you would first have to know their address. In 1852, there were several German Catholic parishes--St. Michael's on Wolfe St., St. James, St. Alphonsus and I believe Holy Cross. The Baltimore City Directories should give you the address that you are looking for. Once their address is known, you can then look for the nearest Catholic Church. Good Luck! Frank Kuhn