I'm trying to find my grandfather's biological mother. John Friedrich Volkmann was born 2/2/1881 in Iowa. He was adopted by Friedrich Volkmann. I believe his mother's name may be Inge Soenksen Henricksen (all three of her names have many different spellings). She was born in Germany in 1858 and came to the USA around 1880. I found a 1900 Census taken in Goodrich, Crawford, Iowa that states John Volkmann is her son. I believe Inge's mother may have been married to Han Jessen.