Let me quote to you a Bishop Missionary from France back in 1791, who basically tells their National Assembly, similar to what "Congress" is today, as to why it would be destructive to France or any part of Europe to end the slave trade and free the slave(workers)....
‘If you were to lose each year more than 200 million lives that you now
get from your colonies; if you had not the exclusive trade with your
colonies to feed your manufactures, to maintain your navy, lo keep your
agriculture going, to repay for your imports, to provide for your luxury
needs, to advantageously balance your trade with Europe and Asia, then I
say it clearly, the kingdom would be irretrievably lost.’
Bishop Maury (of France) : Argument
against France’s ending the slave
trade and giving freedom to its slave colonies.