Weren't you just demanding a Supreme Court decision to prove my point, and you are now offering a Supreme Court decision to prove the opposite of your point?
Are you now agreeing with Scott V Sanford? If not, this is why I don't suggest you put all that much faith into the pronouncements of a "Supreme Court".
Beyond that, this does not even slightly address the point. You cannot use a Supreme Court decision justifying slavery even in Free States, to explain why a Union Army which you claim was fighting to eliminate slavery, did not make the slightest effort to stop it in areas over which they had complete control.
Your response does not even make a bit of sense.
Has nothing to do with “agreeing” with Scott V. Sanford.
One facet of that decision was that the Federal Government did not have Constitutional authority to interfere with slavery in any state where slavery was legal. That is why Lincoln did not use the Federal Army to end slavery in those state that remained in the Union where slavery was legal. He begged, pleaded, cajoled, even tried forms of bribery to get those states to outlaw slavery during the Civil War year. Only Missouri and Maryland outlawed slavery before the end of the Civil War.