Disneyland was built with astonishing speed, taking only one year and one day to complete. Construction on the Anaheim site began on July 16, 1954, and the park opened its gates to guests on July 17, 1955. This rapid timeline was achieved through a relentless, 24-hour work schedule and the personal financial backing of Walt Disney, who even sold his vacation home to keep the project funded. The 160-acre orange grove was transformed into a multi-themed kingdom featuring iconic landmarks like Sleeping Beauty Castle and Main Street, U.S.A., in just 366 days. In 2026, this feat remains a legend in the construction and theme park industries, as modern park expansions of similar scale now typically take five to seven years to design and build. The speed of construction led to several opening-day mishaps, famously known as "Black Sunday," where wet asphalt trapped high-heeled shoes and plumbing failures limited the number of working water fountains, but the core infrastructure proved resilient enough to launch a global entertainment empire.