From the unpublished manuscript, Indian Atrocities Along the Clinch, Powell and Holston Rivers, page 54.
Pendleton, in "History of Tazewell County," page 437, says:
In 1777, a small band of Shawnees came to the head of the Clinch and made John Evans a captive and took him to their towns in Ohio. From thence he was sent to Canada, and either made his escape, or was ransomed, and went to Philadelphia. Jessee Evans, his son, heard of his arrival in Philadelphia and went there in the spring of 1778, and brought him home.
David E. Johnston, History of Middle New River Settlements, page 144, says Evans was captured in 1776.
I have not been able to find any documentary evidence of this capture, and apparently it was another incident that was not mentioned in the military correspondence of the militia officers, or was one of those cases where they only gave the number of people captured, and to our extreme loss, numbers instead of names means little.