Americana: ...Artifacts, or a collection of artifacts, related to the history, geography, folklore and cultural heritage of the United States. Defined as materials and things concerning or characteristic of The United States of America; broadly, its culture. (Definition from Wikipedia)
About this list:
Trying to curate a list of movies that provide a snapshot of late 20th to 21st Century American life, culture or history. This is a work in progress. Feel free to suggest stuff in the comments section.