Answer:
A straw man argument
Explanation:
It is a straw-man argument because of the stated perception that the United States holds for those brought here to be sold and are not considered "citizens." A straw-man argument is someone attacking a thought that a person does not hold i.e. the person attacking is the U.S. even though they shouldn't be the ones to clarify that if they are brought here unwillingly. I believe.
I believe that The Story of the Wolf used by Chief Pontiac is an example of a myth, but I am not completely sure about that.