The Revolutionary War functioned as a civil war in the sense that opinions on the war split families in the colonies. Benjamin Franklin was an ardent Patriot; one of his sons was a Loyalist. This was but one example of many where loyalties divided families and would continue to divide families after the war was over. People had varying reasons for wanting to stay with Britain. Some people saw Parliament as correct and paid their taxes. Others disagreed with Parliament but did not want to risk losing British trade.

Others feared what a new government would look like; though they disliked the way they were currently being governed, they did not want to risk change. Others did not want to risk being taken over by Spanish or French interests in the New World. After the war, the victorious Patriots treated the Loyalists as traitors; many were blackballed from political life or otherwise harassed. Some Loyalists even moved north into Canada, though this was a minority.

The Revolutionary War functioned as an ideological civil war as well. According to the Patriots, before the war they were not treated as Britons with natural rights but rather as an enemy being occupied in time of war. While Loyalists claimed that Parliament had a right to restore order, Patriots claimed that there were limits to Parliament's ruling power when Parliament decided to make laws without colonial consent.

This ideological split made people reexamine what it meant to be governed and what their privileges and obligations would be to that government. This civil war would still be debated after the new nation won its independence in 1783. It would be as divisive as the physical war that preceded it.

As the question implies, the American Revolution was not a simple war for independence from Great Britain—in fact, the war included a fierce conflict between those colonists who supported British rule and those who fought against that rule. As many studies of the conflict have shown, throughout the colonies there were significant numbers of Loyalists who either fought for the British or, in less violent ways, supported Britain's rule. In the southern colonies, which tended to be more conservative than northern colonies, Loyalists may have outnumbered Rebels in many areas. Throughout the colonies, as much as 30% of white colonists most likely supported Britain either directly or indirectly.

Although Loyalists came from all levels of society, many tended to be from the upper property owning stratum—those who had wealth, land, and, most importantly, positions dependent upon the ruling country. In his Origin & Progress of the American Rebellion, Peter Oliver, who was a judge during the Boston Massacre trial, began his (Loyalist) history of the Revolution by noting that

But for a Colony, which had been nursed in its Infancy, with the most tender Care & Attention; which had been indulged with every Gratification that the most forward [that is, badly disciplined] Child could wish for. . . . (Origin, p. 3)

Typically, Loyalists such as Oliver viewed the Revolution as a struggle between a wayward headstrong child against a benevolent father. Throughout the Revolution, the struggle was often characterized as almost a family dispute, albeit a violent one. Oliver, and others of his class, preferred not to see the rebellion as a civil war—that is, a dispute founded on ideas—but as an unaccountable betrayal of the parent-child relationship.

Although violence between Loyalists and Rebels varied greatly during the Revolution, most historians conclude that some level of conflict between citizens was constant during the war and was perhaps greatest in the Carolinas where atrocities occurred almost routinely between the farming and land-owning classes, especially in the later years of the struggle.

After the British surrendered at Yorktown, many Loyalists, as many as 150,000, fled the country. Many fled to Canada and a lesser number to Great Britain. The sad fact is that many, including Peter Oliver, never recovered from the loss of what they believed was their birthright—a successful colony of Great Britain.