Friends attending the Wharton Business School at the University of Pennsylvania encouraged him to join them, so he enrolled there and received an MBA in 1971.

[1] Another friend from Wharton invited him to visit Hilton Head Island, South Carolina, where he met developer Charles Fraser, who offered Rummell a job.

[2] Rummell began his real estate career with the Sea Pines Company in 1971, where he was involved in the development of resort communities on Hilton Head and Amelia Island, Florida.

Beginning in 1977, he was with the Arvida Corporation, where he served as general manager of the Sawgrass development in Ponte Vedra Beach, Florida.

[4][5] Rummell pitched the idea to Disney CEO Michael Eisner in 1989 and described his vision of Celebration: [a] wonderful residential town east of I-4 that has a human scale with sidewalks and bicycles and parks and the kind of architecture that is sophisticated and timeless.

[8] Rummell served as co-chairman of Jacksonville's host committee that was successful in their quest to have the city selected for Super Bowl XXXIX in 2005.