John Bigee's Land Grant was issued by North Carolina in which Revolutionary War veterans were given title to frontier lands in what is now east Tennessee (outside Cherokee territory). I have not found John Bigbee's name in any index of Revolutionary soldiers.
However, the Cherokee James Bigby was born in 1779 in that portion of the Cherokee Nation that was fighting, with British support, against the American rebels in the Carolinas, Virginia, & Georgia. Thus, it is likely that the white father of James Bigby was a Tory, residing with the Chickamauga band of Cherokees.
The diaries kept by Moravian missionaries at Spring Place, GA in the early 1800's suggest that a white man named Samuel Bigby was very likely the father of James Bigby (whose cousin Peggy Scott was the principal wife of Chief James Vann, the patron of the Spring Place school).