I'm including this document 1) as it proves our William Cox was in the Orange County, North Carolina, area by 1770, and 2) it's neat to see his signature and others'
Thomas Brazier made a will in which William Cox, along with John Pyle Sr., was named executor. This is the same family (along with the Pyles and will witnesses Blacks and Panes/Paynes) that the Coxes would inter-marry and travel to SC.
This version, a handwritten copy filed with estate papers, is a little easier to read
There is speculation -- pure speculation! -- that Thomas Brazier's second wife Hannah (last name unknown) could be the sister of William Cox. The only place I've seen this is in the "A Brazier/Brasher Saga" book by Charles Brashear and Shirley Brasher McCoy. If so, Thomas Brazier was born in Maryland and likely married his second wife in Maryland before moving to Orange, NC, according to the authors.