Mary (Knopp)Bartz Dec. 26, 1865 - Nov. 15, 1941 and her husband Carl Bartz Feb. 16,1863 - Nov. 1, 1952. They immigrated to USA from Germany in 1891. I've always been told her mother immigrated at the same time. I don't know mothers name. Carl was Prussian and Mary was from Prussia occupied Poland. Warsaw area is mentioned. Their children's names were Anna, Rosa who is my great grandmother, Charlie, Julia, Eva, and Albert. They resided in Washington county, Iowa. Carl was a farmer and also worked for the railroad. They had six children; Anna, Rosa who is my great grandmother, Charlie, Julia, Eva, and Albert. I'm hoping for any help on the family history in Germany and Mary's mothers name.