Previously, a post on a 1940s video on "modern" Mexico City sparked some good ideas. Here's another. At the Prelinger Archive in New York, this is a World War II-era video by the U.S. Office of Inter-American Affairs on a day in the life of Mexico City.
The video is said to be a reflection of Roosevelt's "Good Neighbor" policy. "Mexico is an old country which is new, a poor country which is rich, a country with more freedom than it has ever known," the narrator says.
* Thanks, Josh K.