I would say Mexico, but it may be Brazil or Spain.
The fact that mostly everyone in the US was once an immigrant is one. Another is that this is a free nation, we should all be treated fairly.
Answer:
A or B but I'm leaning towards B
13th Amendment
Section 1. Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.
Section 2. Congress shall have power to enforce this article by appropriate legislation.