Reedy Creek Improvement Act
The Reedy Creek Improvement Act, otherwise known as House Bill No. 486, was a law enacted in the U.S. state of Florida in 1967 establishing the area surrounding the Walt Disney World Resort (the Reedy Creek Improvement District) as its own county governmental authority, which granted it the same authority and responsibilities as a county government.
Source: Wikipedia — Reedy Creek Improvement Act (CC BY-SA 4.0)