Kappelman Eckerts Living IN Iowa

My great grandparents are Kristoph Kappeman and Barbara Christina Eckert who came to Iowa about 1862 where my grandfather Peter Kappelman was born that year. Kristoph's brother Johann Peter (most records list him as Peter) Kappelman and his wife, Maria Josepha Eckert (sister to Barbara Christina) came to Iowa in 1860. I am looking for more information on the children of Johann Peter and Maria Josepha. Any information would be appreciated.
Thank you