Complex sentence: His early professional life included jobs as surveyor in Glynn County, Justice of the Peace in McIntosh County, and manager of Pierce Butler's rice and cotton plantations on Butler and St. Simons islands, Georgia.
Split into simpler sentences: His early professional life included jobs as surveyor in Glynn County, Justice of the Peace in McIntosh County. He also became manager of Pierce Butler's rice and cotton plantations on Butler and St. Simons Islands, Georgia.