It's been a while since you've posted this notice, but if possible, I would be interested in a copy of this letter. My 2x and 3x great grandfathers are both James Fields born in Loudoun. The elder James was born in Loudoun 1830. In doing the math, he would have been only 19 years old in 1849,so he would not have had 102 year old mother, nor had children old enough to live in Ohio. However, I'm wondering if he was somehow related to the James in your letter.
I look forward to your reply.