Here are a few observations/suggestions:
The listing for Isaac Newman on the 1900 Campbell County, TN census states that Isaac Newman was born Oct 1874 in Kentucky, his father in Kentucky and his mother in Tennessee. The only match that I can find for this information on the 1880 census is at Brush Creek, Knox County KY. (Attached), son of John and Elizabeth Newman. Isaac's age of 7 on the census corresponds to a birth year of 1873 or 1874. And is father was born in KY, mother in TN. The attached WWI draft card for Isaac Frank Newman in Campbell County, TN indicates a birth date of October 20, 1873.
I don't know if this is the right one,but it might be a place to start. You could try contacting

Knox County Clerk
401 Court Square, Suite 102
Barbourville, KY 40906-0105
(606) 546-3568

Good luck!
MR