In 1776, I agree. However, in 1860, I have to consider the possibility that there was a monetary interest in ending slavery in order to dislodge Southern landowners from their land so it can be bought up to ensure a perpetual floor price for cotton.
In your second sentence, you said: "I know the South seceded because the North was trying to end slavery..." so I presumed you were tying the Civil War to the North's desire to end slavery, hence your question about ending slavery as a crass tactic to acquire southern land.
I'm suggesting that it was a moral motivation from the very beginning.
In 1860, I have to consider the possibility that there was a monetary interest in ending slavery
Why? The post-Revolution abolitionism began in earnest in the 1830s. It had its roots in fundamentalist Quaker movements going back to the late 1600s. New York passed a law making slavey illegal in 1827.
If there was a monetary interest in ending slavery, that's because there was a monetary interest in keeping slavery, too. But the larger, more consequential motivations to end slavery have been brewing for over 100 years by then.
A monetary desire to use the ending slavery to buy up cheap southern land as the main reason for it is not supported by history. Now, carpetbaggers from the north during Reconstruction who used the end of slavery to cheat people out of their property is a different matter.
-PJ
Here you go-— the post war takeover of nearly every river location for building industrial textile mills throughout the South. Provides the economic reality to your question— it was always in their mind to both force the Morrill Tariff as well as prevent export of Southern cotton keeping the price high for NE mills. So yes—it was one outcome of the post war poverty (and elimination of a vast number of the male population).
These same mills, converted to steam driven and further- and then, thanks to LABOR expenses and organizing— shut them all down and moved the industry overseas— like to Indonesia. Bibb Mills in Macon, GA did the same, and many more.
Here’s a museum town in NC, Glencoe Mill as an example= a water driven mill:
https://www.ncpedia.org/glencoe