Over years of my life, I have found the only value in movies is entertainment, they are very seldom "Factual"
Fact;
1Jn 3:4 Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.
In the context of this quote the apostle, John was referring to God's law, not man's.
Fact;
There is not one single verse in God's Word (The Bible) which declares owning a slave to be a Sin.
Fact;
Until the 13th Amendment was ratified on Dec 6, 1865, it was not a transgression of the laws of the USA to own a slave.
Fact;
Prior to Dec 6, 1895 owning a slave could not justly be called Sinful.