Disneyland's opening day was a complete disaster. Here is a video from the opening day of Disneyland.
Disneyland was opened to the public on Monday, July 18, 1955. However, a special "International Press Preview" event was held on Sunday, July 17, 1955, which was only open to invited guests and the media. The Special Sunday events, including the dedication, were televised nationwide and anchored by three of Walt Disney's friends from Hollywood: Art Linkletter, Bob Cummings, and Ronald Reagan. ABC broadcast the event live on its network; at the time, it was one of the largest and most complex live broadcasts ever.
The event did not go smoothly. The park was overcrowded as the by-invitation-only affair was plagued with counterfeit tickets. All major roads nearby were empty.
The temperature was an unusually high 101 °F, and a plumbers' strike left many of the park's drinking fountains dry. Disney was given a choice of having working fountains or running toilets and he chose the latter. This, however, generated negative publicity since Pepsi sponsored the park's opening; disappointed guests believed the inoperable fountains were a cynical way to sell soda. The asphalt that had been poured just that morning was so soft that ladies' high-heeled shoes sank into it. Vendors ran out of food. A gas leak in Fantasyland caused Adventureland, Frontierland, and Fantasyland to close for the afternoon. Some parents were seen throwing their children over the shoulders of crowds to get them onto rides such as the King Arthur Carrousel.

The park got such bad press for the "International Press Preview" that Walt Disney invited attendees back for a private "second day" to experience Disneyland properly. In later years Walt and his 1955 executives referred to July 17, 1955 as "Black Sunday". Today, cast members wear pin badges on July 17 stating how many years it has been since the 1955 opening. But for the first decade or so, Disney officially stated that opening day was on July 18, 1955. For example, a 1967 Disneyland press release referred to July 17, 1955, as "Dedication Day" and not "Opening Day."

On Monday July 18, crowds started to gather in line as early as 2 a.m., and the first person to buy a ticket and enter the park was David MacPherson with admission ticket number 2, as Roy O. Disney arranged to pre-purchase ticket number 1. Walt Disney had an official photo taken with two children, Christine Vess Watkins (age 5 in 1955) and Michael Schwartner (age 7 in 1955); the photo of the three carries an inaccurate caption identifying the children as the first two guests of Disneyland. Watkins and Schwartner both received lifetime passes to Disneyland that day, and MacPherson was awarded one shortly thereafter, which was later expanded to every single Disney-owned park in the world.
Other Facts:
- It took only 364 days to build Disneyland.
- Main Street USA is a replica of Walt’s home town of Marceline, Missouri in 1910. (See Marceline above)
- Tomorrowland was originally set in 1986.
- The Autopia ride is the only ride left from Disneyland's original Tomorrowland. By the end of the first day, all but 2 of the 48 Autopia cars were crashed and about half the rides were broken.
- In the early years of the park, the Rivers of America were stocked with catfish and visitors were allowed to fish off the docks of Tom Sawyer Island.