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
I know the Founding Fathers would have liked to have ended slavery as part of the Founding of the country, but they would not have been able to unite the country if they had tried. So, they laid the foundation for its end through the Constitution and Bill of Rights.
The common person of the North may have been more purely intentioned, but the Power interests of the country, I think, were using the virtue of ending slavery out of self-interests because they knew the South could not keep their plantations running without the slaves.