Did you ever find out where Noah was from?
I am also researching Noah Smith because I think he might be related to David Smith b abt 1843 who was also from NC living in Bell Co, KY in 1870. David's family lived in close proximity to Noah's family in Bell Co, KY.
I think Nancy Robbins (Noah's wife) family was from Randolph Co, NC. I wonder if there's any chance that Noah is from Randolph Co as well? Or if Noah and David are related?
In the 1870 census, I also notice that there is a Mary Smith age 50 in 1870 living next door to David Smith's family. I'm wondering if this is David's mother, and if Noah is related, she could be his relative as well.
Hope this helps. I will keep you posted if I find anything else.