I have seen potatoes from Idaho advertised, Avocados from Mexico and Milk from California Cows. So Natural commodities are marketed this way.

Absolutely. These campaigns are all the products of Agriculture Marketing Boards[1] and are generally state-based. They're cooperative marketing agencies which growers and producers belong to to collectively promote their generic product. See also the USDA Agricultural Marketing Service[2].

Idaho Potatoes: https://idahopotato.com

California Walnuts: https://www.walnuts.org

California Almonds: http://www.almonds.com

California Raisins: http://calraisins.org / http://raisins.org

are a few of the domestic ones I've worked with over the years.

EDIT:

Here's a list of all the official California Agricultural Marketing Programs[3]

Speaking of foreign avocados, in addition to Mexico, Chile grows and exports a lot to the US. Of of their interesting arguments is that being in the Southern Hemisphere, their crop is counter-seasonal to our domestic avos. http://avocadosfromchile.org

[1] https://en.wikipedia.org/wiki/Marketing_board [2] https://www.ams.usda.gov [3] https://www.cdfa.ca.gov/mkt/mkt/pdf/ProgramContactInformatio...

Maybe we should eat more turnips and string beans?

I've always wondered why avocados have so much marketing behind them ("Avocados from Mexico" commercials). Seems like they would be in the same boat as other natural foods. I guess it hasn't bothered me enough to do the research, though.