Is warfare ever justified?
Were slaveowners really innocent people, or were they engaged in a lifelong practice of kidnapping, forced labor and other inevitable atrocities?
You didn’t answer my question. If you were being held as a slave, would you be justified in resisting the oppression, even killing your owners? If not, on what basis do you justify American revolution against the British, or for that matter any war? Would Jews in 1940s Europe have been justified in killing SS men?
If you yourself would be justified in fighting back against your enslavers, on what basis do you deny that right to others?
So read the account I posted of the victims - how do you justify their murder? They did not enslave Brown.