I am reading a letter written on September 14, 1863 by Moses Fentress, a member of a north Carolina cavalry regiment recounting the battle of the day before. He mentions Captain Simpson's Company and Captain Cooper's company. Also he names several casualties in Cooper's company: William Smith, Lemuel Shepard, both killed; Samuel Smith was wounded and William Smith of Mt. Pleasant was captured.
I don't think the regiment was the 2nd NC Cav, so it must have been either the 4th or 5th NC Cavalry