Me too! I think I referenced it before on this forum recently, but can't remember. Some years ago, I saw a documentary on PBS that talked about how we went from eating what limited, seasonal, local foods we had available to a more national cuisine, based on immigration, internal migration, the railroad, advanced canning and preserving, and refrigeration. I thought it was called Moveable Feast, but a search for that doesn't turn up the right things (I know it's a common phrase). I can't remember whether that would have been when I was a high schooler, or much later. The concepts stuck in my memory but not the details.
You're right, scarcity during the Depression, plus the more recent developments of mass production of canned milk and foods, made some of those things a Godsend for those who would have been limited to root vegetables in the cellar, cured meats and dried beans in a hard winter outside big cities in the late 1800s.