Would the American Civil War be viewed differently today?

Due to the involvement of the issue of slavery the Civil War is often presented as a noble war, with Abraham Lincoln as a hero. That's how I grew up learning about it.

But if you take away the issue of slavery, as a hypothetical exercise, would we still view it the same way?

Is it morally acceptable in today's world to force States that want to secede to remain? Would Lincoln be viewed as a failure for failing to prevent a war which killed an estimated 2% of the population?

I'm not an expert or even an American and this post is not meant to be political, or lead to a rancorous political discussion

I'm just curious, and curious what people's perspectives are...