The civil war was not fought to free slaves.
This was in the first wave of revisionist history.
You'll dig deep to find records of the New York riots, after Lincoln issued his proclamation.
No one was fighting to free slaves, nor keep slaves.
Well, yes and no. Depends on the perspectives and how deep one wants to look at the causality.
The Civil War was in large part sparked by the Abolitionist Movement. Almost solely based in the Northern States, particularly MA, NY and (yes) VT. Activists who had education and/or free time on their hands (for the first time) decided that they needed to right a perceived wrong. Actually a real wrong. But one that could not be addressed at the time of the Revolution or the Constitutional Convention because the Southern States were needed for a "United" States.
And because of the invention of the cotton Gin and, geography and a number of other factors, the Southern Economy was totally dependant on slave labor. Plus the value of slave 'property' was worth more than all the banks, railroads and factories in the North. So slavey was totally an economic issue. Even many Southerners agreed that slavery needed to end... but saw it as somthing that would happen into the future when A. Slaves were ready. B. When economic replacements were availalbe (labor saving machines... The Irish... etc) So for the South any attack by abolitionists was an attack on their economy and their way of life.
The spark for the successionist movement was probably the Idiot Reverand John Brown whose takeover of Harpers Ferry and 'brilliant' plan to cause a slave revolt... ended up with him swinging from a rope. BUT it suddenly galvanized Southerners to form militias, drill, buy weapons, artillery, etc. And the talk of succession rose considerably. Why? To protect their economics, property and way of life from a Northern Mob (aka John Brown) who was going to try and tell them how to live.
This was exacerbated by the entrance of Kansas and Missouri into the Union. Why? Because noone would allow there to be more 'slave' than 'free' states. On the basis that if the free states got more representation, they would legislate the Southern Way of Life (and Economics) out of existance. This was why during the Constitutional Convention, Southern States were allowed House of Representative Members based on the (non-voting) slave population with each slave being counted as 3/5ths of a person. Allowing more Southern Congressional districts than there were white male landed voters. Bleeding Kansas and the Kansas/Missouri Border wars were another ember on the soon-to-erupt situation.
Then the old Whig party disintigrated and a new party, devoted to abolition, formed. Called the Republican Party. And also devoted to the supremacy of the Republic over the individual rights of the states. Initially small, it attracted a lot of followers as the 1850's progressed. Especially among Northerners and urban populations. Also propelled by a new thing called 'media' and an economic boom that allowed a newly-literate society to read newspapers, pamphlets and participate in politics. One of the 'rock star' events of the era were the Lincoln-Douglas Debates where a (so called) self-made Northern Orator named Abraham Lincoln became a superstar arguing Republican points of view. During this time, the President, James Buchanan... a bilthering idiot... did nothing to calm sentiments or look for an 'out' from the situation of abolitionists vs. Southern States.
When Lincoln was nominated for President, the South assumed that as soon as he was elected, he would abolish slavery. Even though he said, unequivocally, that he would not. He only wanted to preserve the Union and was fully-prepared to work with Southern States to keep them in the Union. Noone believed him in the South. So they seceeded. Basically right as he was elected. Lincoln would not allow them to seceed (which he HAD said he would not allow) and war kicked off at Bull Run (First Manassas).
War came about to preserve the Union as far as Lincoln was concerned. To preserve their way of life, economy and property, according to Southerners.
The "free the slaves" bit came well into the war as popularity for the war was waning in the North and the fronts were stagnated. Lincoln's cabinet felt he needed something 'greater' as a cause. And said it was time to make the war about something greater. He was strongly being pushed by wealthy Northern Abolitionists and Frederick Douglas (not the same guy he debated). Lincoln agreed but said it could not take place until momentum was on the Union Side. And after Vicksburg and Gettysburg, Lincoln felt the time was right and changed the narrative.
And to your point, Chickn, a lot of people in the North were NOT happy with the changed Narrative. Lots of Copperheads and Northern Democrats were utterly against emancipation. But that became the 'narrative' for the rest of the war.
Of course, modern Democrats will have you believe that all the slaves were owned by Republicans, not Southern Democrats. That Republicans formed the KKK, not Southern Democrats. That Republicans firehosed marchers in Selma... not Southern Democrats. That Republicans shot MLK, not Southern Democrats. That Republicans bombed Churches, not Southern Democrats. And that Republicans want blacks in Ghettos and jails, not modern-day Democrats who simply want the African-American vote... while keeping them as a crop inside urban plantations and harvesting them for ballots every two years. The truth hurts, Demo-commies, doesn't it? But since the commies own the media... and the education system... they have the levers of propaganda. And we get to meme about it.
Anyhoo... Pardon my errors and controversial remarks. Going from memory here and only half a cup of coffee so far. So my bad if I screwed up.
Sirhr