Indeed, yes, that was a "massacre", against the rules of war. However...
-- Colonel Charles Lynch of the Virginia militia gave his name to "Lynch Law". That is to say, "give him a fair trial, then take him out and hang him."
-- Thomas Sumter, who gave his name to the now-famous Fort Sumter, hanged so many people, (Loyalists, British soldiers, and even his own men who weren't so crazy as he) that the people hanging from trees became known as "Sumter's Fruit."
He is also called "Tarleton's Spiritual Twin" by historian Hugh Bicheno, author of "Rebels & Redcoats." Both were psychopaths, both murdered people unnecessarily. As you can see, you could try and show both sides of the story.
Also:
Mel Gibson was going to base his film, "The Patriot", on the revolutionary "hero" Francis "the Swamp Fox" Marion. However, it turned out that Marion was a poison-dwarf, who killed without reason, was a racist to the extremes only capable of someone who has been brought up thinking black men are dogs, and who was very short, ugly, and had deformed legs. (He was, however, a very effective leader, and this is no doubt where Mel got his idea from; his own insecurity over his image was no doubt the cause of his extremity of violence.) This is what Bicheno has to say of them:
"Sumter 'the Gamecock' and Marion 'the Swamp Fox' both owned modest plantations near Eutaw Springs on the lower Santee, which were laid waste during 1780 as a result (not, as in myth and film, the cause) of their continued resistance. They were mirror images of Tarleton and James Wemyss.... they tortured prisoners, hanged fence-sitters, abused parole and flags of truce and they shot their own men when they failed to live up to the harsh standards they set."
Marion made his name first by wiping out a column of Redcoats escorting 147 Continentals to Charleston. This is the basis of the incident in the film where Mel uses a tomahawk, traded for with the Cherokee or somesuch, to kill the men kidnapping his son. As we can see, the film is a little inaccurate in its portrayal of the war. The number of books published on the American war of Independence in Britain after "The Patriot" was released is high - academics and historians hated the film with reason, and wanted to set the record straight.
http://film.guardian.co.uk/News_Story/Exclusive/0,,332358,00.html Look here for some info.