As with any particular textbook question, I would strongly suggest ensuring that what is offered here on enotes is consistent with what your text says and what your instructor wants. With this in mind, it sounds like to me that what you seek is how events were read in two different ways by the North and the South on their road to division in the Civil War. The textbook will give you the specific events and may or may not interpret for you how each side saw the event with their own lenses. You might have to read into this on your own. It's not extremely tough, but it does require a bit of thought. For example, the issue of "slavery in the territories" might be something where the South saw owning slaves as an issue of tradition or an issue of exerting their own sense of control over what they saw as something of local concern and not a national issue and certainly not something with which the North need concern themselves. On the other hand, Northern abolitionists saw the issue of slavery as a national or human concern, one that demanded rectifying. Other Northerners might have rejected slavery on grounds that it created an unfair economic advantage for the South, one that Northerners coveted and rather than try to impose on their own simply ought to take it away from the South. This is one example of an event that can be seen from two different points of view, helping to create the chasm that ends up being resolved by the Civil War.