In 1976, American students put their Tricentennial imaginings to paper. Some larger versions of the drawings are available over at Buzzfeed.
Irina Werning has once again recreated the scenes from old photographs in a similar fashion as last time. (slightly NSFW)
The New York World’s Fair of 1939 and 1940 promised visitors they would be looking at the “World of Tomorrow”. (second link is similar to the second one here)