Not almost -- there was a Civil War that tore apart entire communities during the American Revolution. During the war, sections of the American colonies were deeply divided and this played out on the battle fields in dramatic and brutal ways. This was completely magnified in the South, where fighting between American militias completely decimated parts of several states, including North and South Carolina. Civilians were also harmed during this unofficial civil war, mostly by Patriot militias punishing loyalists in barbaric ways. Few contemporary popular works focus on this aspect of the Revolution however. Most stand aside and focus on the Southern strategy of the British in their conquest of these states and ignore the atrocities that battered many towns and villages. But this provides an incomplete understanding of the war in the south where many casualties were made at the hands of fellow colonists, not British soldiers

Books like The Battles of Kings Mountain and Cowpens: The American Revolution in the Southern Backcountry (Critical Moments in American History by Melissa Walker also focus on this aspect of the war, but included some of the internal conflicts that pinned neighbor against neighbor. Some of the biggest areas of contention between these people were loyalists who refused to join and rally at Patriot militia musters throughout the 1779-1781 period. Here, Walker explained that:

In the final analysis, the war in the South was essentially a civil war, and as historian Dan L. Morrill has put it, the backgrountry war inflicted "all the pain and agony that such a political catastrophe brings upon a people." It was that bitter backcountry war that led to American victory, however. Dozens of small frontier battles led to two huge ones: at Kings Mountain and Cowpens. Those battles were the beginning of the end of the pain and suffering backcountry southerners. [pp. 124]

As she points out, Loyalists fought against the patriot militias at the infamous Battle of Kings Mountain, one of the most pivotal battles in the South where patriot militias earned a very brutal victory. This particular battle took place in October of 1780 and was primarily fought between American colonists -- not against British regulars. This battle is symbolic in many ways as a representation of the agony and loss that the South suffered during the war, as Walker points out:

[This battle is] the purest example of the American Revolution in the southern backcountry as a civil war. Ferguson (the commander of Loyalist forces] would be the only man at the battle who was not an American." (pp 77)

Episodes like this stand as a very real reminder of the true brutality that gripped the south during this era. It's also worth remembering that the 'civil war' aspect of these battles wasn't north against south, as what will happen nearly 90 years later. Rather, these militias were made up almost entirely of southerners, with Walker pointing out that less than 100 of the 1100 troops for the loyalists came from outside North and South Carolina [pp 77]. In the end, the Patriots won out, but it was only after they waged war against their neighbors.

Edited: to add additional content

I completely agree with uncovereds answer below and just to add a few more facts if you want to study this in depth.

There was a civil war going in NC that ended bout 1771 with the battle of Alamance. The southern colonies were very much divided in their loyalties. A number of battles in the south featured southern loyalist troops including Camden and Eutaw springs. As uncovered points out: Kings Mountain was fought entirely by american troops.

In the north you dont hear too much about loyalist troops however in upstate NY there was a lot because of William Johnson's relationship with his indian allies. The battle of Oriskany 1777 was one of the bloodiest of battles and is mostly american vs american. That same year also featured Bennington with large number of loyalists fighting for the British. In both of these battles, these were militia type units raised locally and only existing for short periods.