Both Charles Pinckney's from South Carolina were known for supporting slavery, notably the Constitution's Fugitive Slave clause.
But Charles Pinckney also supported abolishing international imports of slaves, and neither Pinckney is known for opposition to abolition in Northern states, or in the Northwest Territories.
Now, I'll grant you that some Southern expressions of opposition to slavery by politicians like Jefferson, Madison, Washington & Patrick Henry may not have been 100% sincere, but they all said it at one time or another, and they supported, or at least tolerated, abolition in other states or territories.
Indeed, Jefferson himself first proposed national abolition with compensation for slaveholders.
So, I'll grant you the Pinckney's from South Carolina, though even they were not as opposed to abolition (i.e., in the territories) as the 1860 era Fire Eaters who cited opposition to slavery in territories as a "reason for secession".
some Southern expressions of opposition to slavery by politicians like Jefferson, Madison, Washington & Patrick Henry may not have been 100% sincere
Which slave-owning Founder opposed slavery so much as to manumit his own slaves?
Did Jefferson manumit his slave Jupiter, who tended to him while Jefferson wrote about all men being created equal?