Answer: the Slave & Trade Act & 3/5ths Compromise was added to it.
Step-by-step explanation:
Southern states like Georgia wanted to protect their slaveholding policies at the time the Constitution was granted and so refused to sign it unless they got certain compromises to protect it.
One of them was the Slave Trade Act which was to stop the importation of slavery into the United States. The Southern States managed to push the date of this Act such that it only came into force over ten years later.
They also demanded a 3/5ths compromise which would see every 5 enslaved people being counted as 3 people for the purposes of representation in the House of Representatives even though the enslaved people would not be allowed to vote.