Which country was the source of most of the illegal drugs, especially cocaine, that were imported into the us during the 1970s and 1980s?

Mexico was the country that was the source of most of the illegal drugs, especially cocaine, that were imported into US during the 1970s and 1980s. The border of the United States of america and the country of Mexico is and was the main entry point of cocaine into America. This has long been a problem for the country of America. 

Two of the countries were subject to imperialism and one maintained its independence is the correct answer.

Explanation: