While I don’t dispute that the practice of Levitical Slavery had probably been corrupted, the actual day to day practice is irrelevant to the discussion as it’s the principle that was laid down in Exodus that is important. Our belief in or practice of a point does not validate that point, it merely reflects on our own morality.
That being said, the idea that Jewish Law was not binding on Gentile Christians is only partially true. After all, Paul pointed out that we were no longer under the law, as the law had been fulfilled by Christ’s death, but His sacrificial atonement was for a covering of our sins and a transferal of His righteousness into our soul. This does not cover some of the other portions of the law dealing with daily life, which is also where a large portion of our legal code comes from.
In the case of Onesimus and Philemon, Paul was in fact reinforcing the idea that Onesimus must keep his pledge of lifetime service to Philemon, while at the same time reminding Philemon that Onesimus was more than just a servant now and to treat him as a fellow Christian. Roman or Greek law may have allowed something stricter than what Paul was saying, but that has no bearing on the situation.
Finally, I never said that American slavery had it’s roots in Levitical Slavery and instead pointed out just the opposite. Because of America’s sins of chattel slavery, and her refusal to repent from it, she was doomed to bloodshed long before the election of 1860 came around.
So Christian converts were bound by obscure passages of the Jewish Law that even the Jews no longer observed?
You have provided not one single point of evidence that would indicate Philemon and/or Onesimus would have felt obligated to follow the rules of Levitical Slavery. Or even been aware of them.
I ran across one comment that Onesimus was a Phyrgian, though I'm not clear on the authority for that statement. If so, he was definitely not a Jew and the Levitical rules would not have been applicable anyway.