And the U.S. Constitution enshrined slavery and said blacks were 3/5 of a human being.
Are you making shit up again?
You should know this stuff:
Article 1, Section 2, Clause 3
Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons.
Article IV, Section 2, Clause 3 - The Fugitive Slave Clause
No person held to service or labour in one state, under the laws thereof, escaping into another, shall, in consequence of any law or regulation therein, be discharged from such service or labor, but shall be delivered up on claim of the party to whom such service or labour may be due.