Comment on Metcalf by Doris Summers

I have not been able to find a marriage record for John A. Metcalf and Mary ?
I have my great grandmother’s death certificate but the informant did not know Octavia’s mother’s name. I checked in White County TN for a marriage record from around 1835 and they didn’t have anything back that far.
Any information you could give me would be appreciated. I got help from Sybil Metcalf several years ago tracing back from John A. Metcalf. I just don’t have any definitive records other than what I found on the census. Can you help?