In regard to your false claim: "I don't recall a single item showing that a single (white) Union soldier fought for abolition as his overriding cause."
You show me nice pictures of 'what's his face' the abolitionist from Boston who commanded the first black Union regiment as depicted in "Glory". So what. You haven't made your case. He wasn't fighting for the abolition of slavery alone. He was fighting for the Union and that was his main drive. He was 26 years old when he gained command of that regiment. What a load.