There are some technologies we really don't think about as "technology," because they were invented so long ago. Canned food is one of those. The technology required to preserve and can food on an industrial scale are surprisingly diverse. Part of the puzzle involves scaling up agriculture itself, but beyond that, canning transforms the economic utility of food. Canning radically redefines the boundaries of food freshness, and smooths out the seasonality of eating. All of these things—plus a dollop of odd jingoism—were on the minds of the 1956 film crew making the documentary below, produced by the American Can Company.
Here's a sample quote:
"Just as harvest time means more than the ending of one bountiful season, it contains within itself the seeds of another more fruitful spring. So this humblest little servant of your daily life, contains not just a product but symbolizes a more abundant life for all freedom-loving people everywhere in the world. This is the miracle of the can."
If you're looking for a soothing video to snooze to, here it is. If you're interested in the attitudes of 1950s America for your Sociology thesis, this is pure gold. Note: Just past the 19-minute part, the film turns into an extended "how it's made" segment.