Well, to explain my point of view I have a number of reprints from the NYT from the civil war.
The news printed just showed the facts.
They did definitely describe each as Rebel vs Union but the facts on casualties seemed to be accurate as possible during that time.
The Times was not slandering the general officers involved and actually showing maps of each sides advance or fortifications.
I do not have the editorial pages.
called for war on economic
the economic editor of the NY Times, who had maintained for months that secession would not injure Northern commerce or prosperity, changed his mind on 22 March 1861: "At once shut down every Southern port, destroy its commerce and bring utter ruin on the Confederate States."
opposed the abolition of slavery and thought a few legal changes would make slavery tolerable
proposed slaves should be allowed to marry and taught to read and invest their money in savings accounts...which would "ameliorate rather than to abolish the slavery of the Southern States."...and would thus permit slavery to be "a very tolerable system." New York Times Jan 22 1861
Nevermind that many slaves already did marry and some were taught to read but....they were still slaves.
goes into detail on why they support war for economic grounds rather than any moral qualms about slavery.
The predicament in which both the government and the commerce of the country are placed, through the non-enforcement of our revenue laws, is now thoroughly understood the world over....If the manufacturer at Manchester (England) can send his goods into the Western States through New Orleans at less cost than through New York, he is a fool for not availing himself of his advantage....if the importations of the country are made through Southern ports, its exports will go through the same channel. The produce of the West, instead of coming to our own port by millions of tons to be transported abroad by the same ships through which we received our importations, will seek other routes and other outlets. With the loss of our foreign trade, what is to become of our public works, conducted at the cost of many hundred millions of dollars, to turn into our harbor the products of the interior? They share in the common ruin. So do our manufacturers. Once at New Orleans, goods may be distributed over the whole country duty free. The process is perfectly simple. The commercial bearing of the question has acted upon the North. We now see whither our tending, and the policy we must adopt. With us it is no longer an abstract question of Constitutional construction, or of the reserved or delegated power of the State or Federal Government, but of material existence and moral position both at home and abroad. We were divided and confused till our pockets were touched." New York Times March 30, 1861
This was not an unusual position to take in the North at the time. They were perfectly fine with the continuation of slavery. What really bothered them was the prospect of seeing their cash cows ie the Southern states, leave.