I've been doing some research, and I came across this documentry made originally of Futurama by GM. Futurama was one of the most popular exhibits in the 1940 Worlds Fair, as it was a look by them 20 years into the future. It was apparantly adapted for a documentry style propagandist style film not long after. (And yes, where the TV show Futurama got its name)

It's amazing to see the way the world of 1940 looked to the upcoming world of 1960, with the "idea" of the highway, with expressway turn on and off lanes as if it's a miraculous idea, the widespread use of electric power, and the redesigned cityscape of tomorrow. Especially given that WWII and the beginings of what would be the cold war was stirring globally at the time hadn't yet happened; before the wars and the Nuclear family, and all the staple ideals that we usually think of that represent the past.

You can stream or download it yourself here: http://www.archive.org/details/ToNewHor1940

I suggest jumping to around the 8 minute mark, as the first seven minutes are a rather boring look at development up to the 1940's for schoolchildren for contextual purposes. (And makes the jump into Technicolor at that point.)

Oh, and the ending iconography made me chuckle.