Achterberg family, late 1800 immigrants

I am looking for a Walter ACHTERBERG, possibly in Tyndall or Tyndale who was living in South Dakota in 1918-1919.I believe his father was Paul Achterberg, born in Pommern, Prussia and I don't know his mother's name. I would also be interested in hearing from anyone with the name of ACHTERBERG - it's not that common and I have a feeling they will all tie together in the end!