Complex sentence: Gunderson was born in a log cabin in Clay County, Dakota Territory, near Vermillion, South Dakota, and as a young man filed a claim on a homestead in Clay County, South Dakota, that remained dear to him all his life.
Split into simpler sentences: Gunderson was born in a log cabin in Clay County in the Dakota Territory, near Vermillion. As a young man, he filed a claim on a homestead in Clay County that remained dear to him all his life.