Coon is a slur used to describe Blacks in a derogatory way. Probably refers to the Portuguese word for slave pens or barracks "baracoons". Could also have meaning as a shortening of "raccoon", as raccoons have a tendency to steal.
Possibly from Dr. Carleton Coon, who, in the mid-1960's, theorized that blacks were
The word Coon is a racial slur that has been used historically to degrade and dehumanize blacks. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to blacks. If you are unsure about whether or not it is appropriate to use the word Coon, it is best to err on the side of caution and avoid using it in any situation.