I am researching Nance families originating in Union County, SC, and I have entries from US Census 1790 - 1920 showing all Nance surnames in Union County.
Sherwood Nance appears on the 1810 Census for Union Co. under Sindex# N200.I got this info from Paul Surratt, Jr.
The number M-252 appears by each person's name, and I don't know what this refers to.You would have to have the original record of the census to determine what it represents.It probably refers to a certain part of the census where the Nances are listed or maybe a NARS# which I don't know what that stands for either.A genealogy research librarian could probably tell you what these numbers mean.They are all also on Reel #61.
So the record that was copied for Sherwood Nance is:
Sherwood Nance#M-252, #61, #234, NdRcd
"NdRcd" means "Need Record".Because this census is so early, members of the household were not shown.The #234 is either the page number or the household number.I am told that the names listed are heads of households and each household has a different number.
Along with Sherwood Nance on this census is: Betsey, HH#230 ------------------Same number means persons reside in same household. Charles, HH#233 Isaac, HH#244 Thomas V., HH#230 ---------------Same number means persons reside in same household. William, HH#239 Zachariah, HH#245
I don't know if this will give you any clues as to why he appears in your Bible.Perhaps if knowing of some other Nances living in Union at the same time as he, may provide a clue.
If you don't know of any Nance relatives, perhaps he was related to you through a female relative whose maiden name was Nance.