In 1938 Mexico nationalized America's oil, according to my textbook. What does this mean? I don't get what exactly they did.
http://www.google.com/#hl=en&source=hp&q=In+1938+Mexico+nationalized+America%27s+oil&aq=f&aqi=&aql=&oq=&gs_rfai=&fp=a2bb30ecf4f91972
Read several of these to understand.