Complex sentence: He later sold his ferry and land claim to Nimrod Phillps, many of whose descendants are still living in Pike County, Illinois first surveyed by the government in the years 1817-1819.
Split into simpler sentences: He later sold his ferry and land claim to Nimrod Phillps, many of whose descendants are still living in Pike County, Illinois. It was first surveyed by the government in the years 1817-1819.