Mr. Thornton was elected a Trustee of the Alfred I. duPont Charitable Trust in 1967 and served as Chairman of the Trust from 1982 until 2005. He was also elected to the Board of Directors of The Nemours Foundation in 1967 and served as Vice Chairman until January 2005. He began his career in railroading with the Southern Railway in 1950, moving to the Florida East Coast Railway (FEC) in 1960 as Chief Operating Officer. He was subsequently elected Vice President, Director, President and Chairman of the railway, and then Chairman, President and Chief Executive Officer of FEC Industries in 1984. He retired from FEC Industries in 1997. Mr. Thornton was first affiliated with St. Joe Paper Company as a Director in 1968 and was named President in 1984 and Chairman and Chief Executive Officer in 1991. He retired from the St. Joe Corporation in 1997 and served as a member of the St. Joe Board of Directors until 2004.