Cheryl, this sounds like it could be the same Martin Knapper. My great grandfather was married twice, he had Fred, mymy grandfather from what I have heard his first wife died maybe giving birth to my grandfather. He then remarried and had 3 more childrenDan and George and a daughter, not sure what her name is.I would really like to hear more about your family. My parents went to Minn once to visit my dads uncle Dan.I wish I had gotten more information when they were alive.It would have saved some hard work now. please contact me.