Complex sentence: He first moved to Hershey, Pennsylvania in 1917, where he enjoyed a relatively prosperous job on a dairy farm owned by The Hershey Company until the farm was closed by Hershey's.
Split into simpler sentences: He first moved to Hershey, Pennsylvania in 1917, where he worked for on a dairy farm owned by The Hershey Company. He did well until the farm was closed by Hershey's.