[Q. Every major newspaper in the country had said so by January, when Buchanan's attempt at Sumter met with 5 more states seceding; it was about money, not slavery..
For the North- the war was always about maintaining the United States.
For the South- the war was about maintaining slavery- certainly they had other issues- but slavery was as it had been for decades- the big issue- if you want to check- read the newspapers in the South.
Charleston at War: A simple Ordinance of Secession