Parks on 3 continents kicked off a marketing campaign celebrating Disneyland's birth.

Walt Disney World joined Disney parks on three continents Thursday in launching an 18-month-long marketing campaign celebrating the 50th anniversary of Walt Disney's original Disneyland in California.

Legendary entertainer Art Linkletter, who presided at Disneyland's opening in 1955, walked slowly onstage to applause at Disneyland once again and helped kick off the festivities.

Parks in Tokyo, in Paris and in Hong Kong, where the 11th Disney park is scheduled to open in September, also are participating, along with the Disney Cruise Line, in the company's first worldwide promotion. "It feels like only yesterday," Linkletter said of the opening a half century ago of Disneyland, the small park that launched the modern theme-park industry.

With the same twinkle in his eye and smile that endeared him to generations of children and families, the 92-year-old Linkletter declared: "Over the years, it's been wonderful to watch Walt's dream spread."

More than 200 VIPs and special guests at Walt Disney World tossed commemorative, gold-colored Mickey Mouse ears into the air at the conclusion of the singing of "When You Wish Upon a Star." Thousands of visitors from many states and countries crowded in front of Cinderella Castle to watch, and a large screen showed events via satellite from Anaheim and shots from the other parks around the world.