By the time the Magic Kingdom opened on October 1, 1971, more than 9,000 construction workers had labored for 18 months to build the park, which cost approximately $400 million to create.

The construction of Magic Kingdom at the Walt Disney World Resort in Florida was a monumental financial undertaking, with an initial investment of approximately $400 million by its opening on October 1, 1971. Adjusted for inflation, this figure would exceed $3 billion in 2026 dollars. At the time, it was the largest privately funded construction project in the world. The project involved not only the creation of the theme park's iconic lands and attractions but also the development of a massive 25,000-acre site that required extensive drainage, the construction of the Seven Seas Lagoon, and the creation of a sophisticated "utilidor" (utility corridor) system beneath the park. This tunnel network allows cast members to move out of sight and houses essential services like trash removal and electricity. While the initial $400 million covered the park and the initial two resorts (Disney's Contemporary and Polynesian Village), the cost of the entire resort has grown into the hundreds of billions as Disney continues to add parks like EPCOT, Hollywood Studios, and Animal Kingdom.