US Constitution the words slave or slavery do not appear in the constitution yet they are certainly referred to it. there are 3 clear references and several other less direct. What are they?

1. The 3/5 clause which says that an enslaved person will only count as 3/5 of a person in the census.

2. ban on middle passage slave trade.

3. fugitive slave clause which says any slave who runs away automatically has to be returned to its owner