Hi Terrance,
The book which contained the story of John Redman and Cassie is called Loudoun Valley Legends by Joseph V. Nichols. Mr. Nichols got the story from Flave Redman, whom he said was a grandson of John and Cassie, but that was not the case. Flave was at least a great grandson of John and Cassie, as Flave gave the information for his father's death record and stated that his father's parents were George W. and Mary E. Redman. Mr. Nichols based his estimate of the time that John Redman met Cassie on the belief that they were Flave's grandparents and said that the meeting was about 1790. Their meeting had to have been much earlier than that. If you think that you descend from John and Cassie, I will be glad to try to help you to figure it out if I can. The book only has a very short chapter on John and Cassie but can be purchased at the Thomas Balch Library in Leesburg, Loudoun County. You could probably get it on library loan also, as many libraries have it.
Bill