Whys it's important to study primary sources from the civil war and give an example

Its import to study the primary sources from Civil War because the Civil War was fought between the north and the south the north thought that there should be no more slavery but the south wanted slaves to pick the cotton in the farms and most all slaves were African American (Black). It also shows that we were also once a separated country and that there was territory and border states so in all that is why its important to study the primary's of the Civil War.