Thirteenth Amendment (1865)

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.

The Thirteenth Amendment freed the slaves. The Emancipation Proclamation did not apply to all the states. The Thirteenth Amendment abolished slavery entirely. It also gave Congress the authority to enforce the amendment through legislation.  

The following cartoon celebrates achievements in the fight for racial freedom. Slavery was abolished once and for all with the ratification of the 13th Amendment, but Jim Crow laws were soon created to push for segregation.
http://daddybstrong.blogspot.com/2008/12/13th-amendment-happy-freedom-people.html

The following video takes a stand against human trafficking arguing that it is a form of involuntary servitude. I definitely agree. Involuntary servitude is protected against by the 13th Amendment. Human trafficking is modern day slavery. United States' citizens need to stand up and fight against it.