The Food of A Younger Land, by Mark Kurlansky, was interesting. It's one of those books that I don't really feel like reading cover-to-cover, but end up skimming some chapters and reading others (usually not in order.) He comments and adds history to a previously unpublished WPA writer's project from 1940, which studied the food and eating habits of America before we turned into a generic nation. Wonderful writers like Eudora Welty, Zora Neale Hurston, and others contributed to the original sections.
Along the lines of Fast Food Nation (the book not the movie.) I found it very enlightening, but more so to a foodie like me than Fast Food Nation was. I LOVE how the recipes for many regional dishes are in there. As a child of the 70's and 80's I was already one from the generic nation of food I think. How much has changed in so short a time.