He appears in the 1785 Kenton Hundred Taxables List which included Little Creek Hundred indicating he continued to live in the same general area as his family.

In 1788 he was mentioned in the will of his father.

Isaiah died in 1793. His estate papers mention his widow, Mary, and the following children:

1. Pheby Durham
   
2. William Durham
   
3. Elijah Durham
   
4. Margaret Durham
   
5. Isaiah Durham
   
6. Rebeccah Durham
   
7. Jeremiah Durham
8. John Durham
   
9. George Durham (d. 1844)
   

The widow, Mary, appears in the 1800 federal census, living in a household of 10 "free colored persons". Sometime between 1800 and 1803 she re-married, John Sisco and went to live at Bloomsbury, the site currently be excavated by Ned and Louise Heite.