Complex sentence: In 1821, Harvey Ross moved with his family to Fulton County, Illinois and settled in the area that became Lewistown, which was founded by Ossian Ross and named for his oldest son, Lewis.
Split into simpler sentences: In 1821, Harvey Ross traveled with his family to Fulton County, Illinois and settled in the area that became Lewistown. The town was founded by Ossian Ross and named for his oldest son, Lewis.