Slavery is the main issue with the Civil War. It is couched in a "you can't tell us what to do economically", but the right to use slaves was 100% the point, the very thing that was being "squeezed" in their agrarian society. You can say "the war was about economics", but the only thing the north, and centralized national power, took exception with in the south was their use of slaves to bolster their economy. The right to hold slaves shows up over and over again in the individual articles of secession. Yeah, it was "economic squeezing". It was the industrial north becoming a stronger economic region. But there was only one thing the executive office and the central power of the northern states wanted to restrict within the operations of the south. And that was human slavery.
So, yeah...it was about economics. The economics of using slave labor...the south said they would be bankrupt without it, the north said "that's not our problem...stop the practice" and war commenced.
Whether the mindspace of all northerners, or even Lincoln, was in a perfectly correct space regarding African Americans (referred to as blacks, or negros at the time ) is really a side discussion, because it doesn't change the reason for the aggression, which was the south's steadfast position that slave labor was necessary to turn profit.
Even in its most meandering articles, like South Carolina, the reference to southern brothers in secession is referred to as "slaveholding states":
"The people of the State of South Carolina, in Convention assembled, on the 26th day of April, A.D., 1852, declared that the frequent violations of the
Constitution of the United States, by the Federal Government, and its encroachments upon the reserved rights of the States, fully justified this State in then withdrawing from the Federal Union; but in deference to the opinions and wishes of the other slaveholding States, she forbore at that time to exercise this right. Since that time, these encroachments have continued to increase, and further forbearance ceases to be a virtue"
Not the other southern states. It was recognized what their common bond was, and it wasn't simple geography. It was they were slaveholding states, the central US government wanted to end slavery, and they weren't going to let it happen. So yeah...it was economic squeezing