The North wasn't a single, unified entity. There were 4 major polities in the Union during WW2:
- New England and the Great Lakes were virulently anti-slavery for primarily economic reasons, but some moralist reasons also.
- New York City was mercantile and not thrilled about being in the war. Lots of protests and political violence in NYC during the Civil War.
- Pennsylvania and the Lower Ohio Valley were generally more anti-slavery for moral and economic reasons, but generally more pacifist and amiable toward the South than New Englanders.
- Appalachia, which covers all the border areas along the mountains running from central PA to northern AL, who were completely ambivalent about slavery, but extremely patriotic and anti-secession.
Pre-1860 a vote on slavery certainly would have failed in the North and may have led additional states to secede. Lincoln was explicitly not pro-abolition for this reason.
- New England and the Great Lakes were virulently anti-slavery for primarily economic reasons, but some moralist reasons also.
- New York City was mercantile and not thrilled about being in the war. Lots of protests and political violence in NYC during the Civil War.
- Pennsylvania and the Lower Ohio Valley were generally more anti-slavery for moral and economic reasons, but generally more pacifist and amiable toward the South than New Englanders.
- Appalachia, which covers all the border areas along the mountains running from central PA to northern AL, who were completely ambivalent about slavery, but extremely patriotic and anti-secession.
Pre-1860 a vote on slavery certainly would have failed in the North and may have led additional states to secede. Lincoln was explicitly not pro-abolition for this reason.