When DISNEYLAND was being designed, Walt Disney was dissatisfied with how Tom Sawyer Island was being designed. It just didn't look right to him, so he took the blueprints home one night and brought them back changed to look exactly the way he had envisioned.
Having grown up in Missouri, just like the fictional Tom Sawyer, Walt Disney had an affinity for the state and the state was proud of him. A longstanding rumor is that Tom Sawyer Island was legally annexed into Missouri and guests making the boat ride to the island were crossing state lines. It was claimed that the park didn't sell merchandise or food on the island because it didn't want to worry about different sales tax rates or corporate taxes.
The story is partially true. The state of Missouri "annexed" the island in an honorary ceremony. The island itself remained legally inside California and actually sold items up until the mid-1990's, charging California sales tax and following California laws.