Overall yes, you’re correct- the North was heading that way but the abolition of slavery was the stimulus for northern domination ---- But in the lead up to the war, no - the south had the economic power
Let me go all @Cicero_Dandi if you will…
look at the value of slaves here in the immediate pre -war years
Look at the slave related income of whites in the two big slave states
Cotton produced by slaves counted for 60% of all exports from America - look at it rocket in the lead up to the war…
The North of course benefited from this as they sent goods South to appease Southern demands for luxuries.
But you are looking at two different societies here also agrarian v urban - As you mention, the rise of capitalism in the urban North was growing and lead to them wanting to break the Southern market - -The North became a market and much more politically aware - the South’s development was stagnant and closed off… In essence, the South were resisting the advances of the market economy.
Slavery was the cause alright ---- but not for moral reasons… they were very low down on the list.
The Declaration of independence and the American proclamation are nothing more than business documents putting the future of America in the hands of a few white capitalists - and telling the previous owners that they no longer do business here.
The Confederacy the animals and staunch racists that they were had a native American Cherokee General named Stand Watie, this was almost a decade before a Union “hero” of @glasagusban one George Armstrong Custer would terrorise the native Indians using their women and Children as human hostages before meeting a sticky end at little bighorn.
Don’t be offended because someone has more knowledge on a particular subject, it’s ok your still top dog when it comes to hill walking and cooking jam tarts.