When was Disneyland founded?
Disneyland in Anaheim CA was opened exactly one year and a day after it was announced. It had it's press release on July 17, 1955, and was opened to the public on July 18, 1955. Disneyland has 1 sister park called Disney's California Adventure which opened in 2001 along with the Downtown Disney District and the 3 official Disney Hotels making it a resort. (Disneyland Anaheim is the only Disney park to be seen by Walt Disney, he died before and other park was planned.)
Orlando usually said to have Disneyland does not actually have a Disney park. The Disney park is actually located at Lake Buena Vista FL. Also the park is not called Disneyland it's called Magic Kingdom. The park was opened on October 1, 1971. The park also has 3 sister parks in the Walt Disney World Resort. EPCOT, Disney's Hollywood Studios, and Animal Kingdom are the sister parks. WDW also has 2 water parks Typhoon Lagoon, and Blizzard Beach.
Tokyo Disneyland was the second park opened with the name Disneyland third Disney park and first park outside of the USA. Tokyo Disneyland opened April 15 1993. This park is not owned by Disney but the Japanese company, The Oriental Land Company. This parks sister park is Tokyo Disney Sea which is considered Disney's best non magic kingdom style park.
Sorry I just wasn't sure which park you were talking about there are parks in Paris, and Hong Kong.