For all the attention paid to shiny new features at Florida's Magic Kingdom, Tokyo Disneyland or the under-construction Shanghai Disneyland, there's only one original Disney park.
On July 17, 1955, Walt Disney welcomed thousands of invited guests and gate crashers to preview the first Disneyland on a 160-acre former orange grove in Anaheim, California.
On that invite-only opening day, crowds overwhelmed the park, which cost $17 million to build but was not quite ready for prime time. The park opened to the public the following day.
Disney and his team quickly responded to early problems of wet paint, ride breakdowns, a gas leak, plumbing problems and food shortages, continuing to tinker with the first park in what would one day be a worldwide empire.
Some 20 years in the making, Disneyland the only park that Disney worked on personally, often spending the night on the property in a small apartment above the Fire House on Main Street, U.S.A.
When the park opened, there were just 18 Disneyland attractions spread across Main Street, U.S.A., Fantasyland, Frontierland and Adventureland.
Now there are 11 Disney theme parks worldwide, part of the Walt Disney Corp. -- including resorts, cruise ships, movies, television shows, toys and more -- that saw revenues of $12.5 billion for the six months ending March 28, 2015
What would eventually be the Disney empire was no guarantee in the early days.
"It started with my taking my two kids around to the zoos and parks," Disney said later, according to an official company account. "While they were on the merry-go-round riding 40 times or something, I'd be sitting there trying to figure out what you could do that would be more imaginative.
"Then when I built the new studio in Burbank, I got the idea for a three-dimensional thing that people could actually come and visit. I felt that there should be something built where the parents and the children could have fun together."
Famous by that time for his movies, Disney found inspiration in developing his ideas -- often off the company payroll and sometimes without the support of his brother, Roy.
Walt Disney tapped into his personal wealth to finance Disneyland's development, and eventually he turned to the American Broadcasting Company to help finance the park. ABC agreed, in exchange for a weekly television show. The Santa Fe Railroad and loans covered the rest.
Disney's development of the park was heavily influenced by the tenor and values of Cold War politics, and his wish for cleanliness, safety and order.
"There's an American theme behind the whole park," he told columnist Hedda Hopper, according to "Walt Disney: The Triumph of the American Imagination," by Neal Gabler.
"Disneyland was intended to re-create not only Walt Disney's moment of possibility but also America's, when the country, like Walt, had been both innocent and ambitious," Gabler wrote in the book. Disneyland was not just an amusement park, he wrote. "It was also a repository of values."
While amusement parks had been around before, many had not been quite so clean and wholesome or staffed by well-trained employees.
Disneyland was truly new and original, says Manchester University sociology professor Robert Pettit, who teaches a three-week winter course, "Disney and American Culture," that includes a Disney World site visit.
"What made Disneyland unique and transformative was its structuring of the park experience with Disney stories and characters -- the first and still most effective use of immersive 'theming,' " Pettit told CNN.
"Park 'guests' -- not customers -- entered Walt's imagination in 3D space and surround sound, totally enveloped in the Disney universe they had loved on the movie screen. There was nothing else quite like it, and folks had to travel to Anaheim to get that experience. And they did, by the droves," Pettit said.
"Intellectuals and academics were initially quite unkind to Disneyland, delighting in exposing its commercialism and supposedly innocent narratives colored by traditional American racism and sexism," said Petitt. "By the 1980s, different critical viewpoints began to emerge, less ideological and more interested in the consumer tastes and narratives that make Disney parks so popular.
"Indeed, if you want to understand American culture, there is no more revealing object of study than the Disney parks," Pettit said.
"How else do we understand their enduring appeal than to realize that they have tapped into the American subconscious, knowing how to express it and appeal to it better than just about anyone else?"