Originally the first types of parks were established in the late 19th century. But their original purpose wasn't to keep us entertained, but to "make us behave better" Some of the first people to establish the parks actually believed that they could reform the local population by doing so.
The thought that they could get rid of the prostitution, drunks, and other foggies by letting them have more recreational activity in the parks. But while their intentions were well meaning, they obiviously did not come to pass.
Now when you go to a park, people do all of their drinking, lewd acts and other disgraceful behavoir in parks. And if you read an artical on the Save Disney Website, this one guy who played Moglie at Disneyland in the 1960s, he states that his favorite spot to have sex with the girl customers was Snow White's house.
That and the fact that Disneyland went up at the high point of the Cold War, when the world almost came to an end.
So maybe Walt Disney had help from the government to assist in creating a theme park to make us behave better, when we obiviously couldn't tell jokes about the Russians at that time. 
