My brother and I participated in the Tow project in Family Tree DNA and we got the same result that you did. No Native American at all in our DNA. Not on the male side or the female side. We are about 85% western European and 15% Eastern European.
Like you I am a descendant of Wilson Tow and Margaret Moseley/Dunwoody. (I've never been able to figure out if which was Margaret's maiden name and which was her first married name.)