...the southern slave plantation bourgeoisie kicking and screaming into industrial capitalism.
The slave economy was a drag on the more developed form of capitalism that was about to revolutionise the world. Everything else is just window dressing and fancy speeches.
this paints it like the north was the aggressor.
they categorically were not. even in terms of bourgois competition, all the north wanted was to preserve (some) western territories for future free expansion (on native land) and existing non-slavery territory.
The two economic systems were on a collision course, who was the aggressor is kind of irrelevant (to this discussion anyway). Freeing the slaves for humanitarian reasons was an afterthought.