CELEBRATION, Fla.-In November, 1996, Walt Disney Co. unveiled the nation’s first Disney-built theme town, an 11-square-mile enclave near the Magic Kingdom designed to be a modern-day suburban Utopia. Homes the color of orange sherbet and buttercream frosting were graced with picket fences and Southern-style porches, intended to create an old-fashioned sense of community.

Celebration, as it was called, was the outgrowth of a fantasy…