I have a rule

Kanye West Calls Slavery A ‘Choice,’ Gets Schooled On History

Until about 1810 it was about multi-racial colonial, servitude, blacks getting the raw end.  From  1810 until 1855 it was southern plantation, mass farming, back slaves only. After 1860 it is multi-racial labor law,  blacks getting the raw end. 

A short encapsulation of history, add whatever moral values you choose. Consider another group, mexican farm workers in California. Racist employers, low paid, bad conditions. One other thing, the California hispanic has been farming like that for 100 years before yanks arrived. If servitude had been abolished, blacks would have gotten shity cotton jobs, my point.  But the South put race into their constitution, stupid.

In the north, long term servitude was unenforceable, regardless of race. There were too many migration opportunities for the indentured.  The South expecting the North to restrict by race without precedent.  The South doomed from the start, their economy having being a one shot, bubble plantation system.