Complex sentence: Soon he emigrated to the frontier of the Indiana Territory where he was an early pioneer he met and subsequently married around 1808 Rhoda Sampson the daughter of William and Sarah (Coleman) Sampson in Harrison County, Indiana.
Split into simpler sentences: Soon he emigrated to the frontier of the Indiana Territory where he was an early pioneer. He met and subsequently married, around 1808, Rhoda Sampson, the daughter of William and Sarah (Coleman) Sampson in Harrison County, Indiana.