The last major project at DISNEYLAND that had Walt Disney's personal stamp on it was Tomorrowland 1967. Mr. Disney had seen how the every day world had caught up with his Tomorrowland, so he planned to tear it down almost completely and rebuild it from the ground up.
The new land would feature a futuristic new transportation system- the People Mover and one of the attractions that had originally premiered at the 1964 World's Fair- the Carousel of Progress. The centerpiece of this new land was originally going to be Space Mountain, but when the imagineers couldn't figure out a way to make it work the way Mr. Disney wanted, he put the project on hold. (It would finally get built the way Walt had wanted in 1977.)
When Walt Disney did a renovation, he really did a renovation. Over 90% of Tomorrowland was completely closed down in 1966 to accommodate construction. Models and signs were placed right outside the construction walls to pique the interest of guests. Despite the death of Mr. Disney in 1966, construction continued to meet the opening deadline of 1967.
As a sign to investors that the company would continue past the death of Walt Disney, the all new Tomorrowland opened as planned in 1967- a true World on the Move.