Was the american civil war really not over the slavery? What were the main reasons behind the opposing sides? I find myself in a very difficult position in which I cannot trust either side.
I strongly recommend that you check out our FAQ on Slavery and the Causes of the American Civil War.
This has been asked here many times in various forms.
The simple answer is - it was about slavery. Other factors existed, but to suggest it was not about slavery is simply wrong
The most detailed answer I've seen on the topic can be found as top comment in the thread I link below. It is normal to tag the user in question when linking answers like this, however in this instance I choose not to due to the incredibly complete nature of the answer, and also being unwilling to bug the poster for what I am sure will be the millionth time about the same question, given how often his answer is linked across this subreddit. Hopefully the mods will be understanding about that rationale.