Kings Mountain is a unique battle for several reasons.  It was one of the few major battles of the war fought entirely between Americans: no British troops served here. In the South, many people were divided.  When the war started, some fought for independence, others for loyalty to England.

Kings Mountain is also unique in that large numbers of riflemen fought here.  Rifles were not used much by the armies.  A rifle was a hunting weapon, used by families on the frontier.  The American militia that fought here mainly used rifles; the Loyalist troops had mostly muskets.
The difference between a rifle and a musket is speed versus accuracy.  A rifle is slow to load, but very accurate.  Riflemen can hit a target at 200 or 300 yards.  Yet the rifle can only be fired once a minute.  A musket, with a smooth bore, is easy to load but inaccurate.  Muskets have an accurate range of about 100 yards, but can be fired up to three times a minute.