Thank you so much! Yes, this is my Smith line. I descended from his brother David.
I noticed that David and Noah were living in close proximity in the 1870 Bell Co Census and that a Mary Smith, (age 50 in 1870, so born about 1820) was living next door to David. All were listed as being born in North Carolina.
So it sounds like David and Noah were brothers and that Mary is his mother afterall!
David's son, Lemuel Redman Smith (b Feb 25 1869 - my gg-grandfather), married Margaret Robbins b Sept 1867. Margaret was the daughter of William Alexander Robbins (Nancy Robbins brother), who were also living nearby in the 1870 Bell Co census.
I have a picture of Lemuel ("Red") I could send you if you'd like.
I would love to hear any stories you would like to share!