After the thirteenth amendment became part of the constitution,
the south could enforce the black codes.
segregation was outlawed in public schools.
african americans gained the right to vote.
slavery became illegal across the united states.

slavery became illegal across the united states after the thirteen amendment

Explanation:

The thirteenth Amendment was made/passed by the senate on April 8 1864 by the senate of the united states of America. It Abolished Slavery and involuntary service from been imposed on people/inhabitants of the USA. but it supported that slavery can be used as means of severe punishment for crimes been committed.

This Amendment was later consented to/signed by the required number of states on December 1865 to make sure that slavery became illegal across the united states  

The Amendment was necessary because the rate of slavery was very disturbing and severe in the United states

the correct answer is history and tradition.