[BroJoeK]

PeaBrain: "Brojoke and his cohorts do not want to admit the truth.
Following secession and up and until two weeks after Lincoln took office, a large part of the northern press contended that the States of the South had a full right to secede if the people desired to withdraw from the Union, and it was common to see in the northern press the words, 'Erring sisters go in peace.' "

Sure, some did, but the majority of Northern opinion was actually closer to that of Democrat President Buchanan.
Buchanan believed, and said so, that the Constitution does not legitimize unilateral unapproved state declarations of secession, but that the Federal Government could not do anything to stop them.

Incoming President Lincoln also followed that line of reasoning, in his Inaugural telling secessionists:

"Intelligence, patriotism, Christianity, and a firm reliance on Him who has never yet forsaken this favored land are still competent to adjust in the best way all our present difficulty.
In your hands, my dissatisfied fellow-countrymen, and not in mine, is the momentous issue of civil war.
The Government will not assail you.
You can have no conflict without being yourselves the aggressors."

But, of course, secessionists had every reason to start war, and so they did, at Fort Sumter.

That changed everything.

PeaBrain speaking of Northern economic interests: "Or they would trump up some fake reasons to go to war and attempt to destroy the competitor."

But as it happened, there was no need for any "trump up", since Confederates were already eager to start war and took the first excuse they could, then quickly declared war and sent military aid to Confederates in Union states, thus sealing their ultimate fate.

And as a result, "war fever" became just as great amongst average Northerners as it had been among Fire Eater Confederates.

[PeaRidge]

Brojoke: You gave this Lincoln quote.....

“The Government will not assail you.
You can have no conflict without being yourselves the aggressors.””

But you did not think this one was important?

“The words `coercion' and `invasion' are in great use about these days.

"What, then, is `coercion'? What is `invasion'? Would the marching of an army into South California, for instance, without the consent of her people, and in hostility against them, be coercion or invasion? I very frankly say, I think it would be invasion, and it would be coercion too, if the people of that country were forced to submit.” - Abraham Lincoln, February 11, 1861

He sent the Navy down to do just that two months later.

Lincoln: "But what about my tariff."