The 13th amendment was passed and ratified around the civil war between the north and south.
It states that you cannot have slaves unless as punishment however when it was passed it only freed abt 1% of slaves in the south until it was ratified.
The importance of this is that it undid the effects of the 3/5 compromise meaning that slaves would be counted as a person each instead of doing one person every 3 out of 5 slaves.
It finally recognized slaves as humans.