Hello T.

At this point, it is imperative to move from the known - there are too many unknowns.

Known:
1) James' approx. birth and death dates
2) His Death PLACE and approx. date
3) His Wife and some of their children
- Where did he meet her?
- When did she die?
4) He owned land in Montgomery County
- Was it 'deeded' over to his daughter and/or son-in-law? [records]
5) He is in the Census records from 1870 to 1920

In one of the many books and papers written about the McCauleys, it mentions that the family story is that James Percival went to work for the "Wright Family" of Pine Level.

Now, I don't know if that was BEFORE or AFTER the Civil War, but it is worth a follow-up (especially if it was before the Civil War).

- Per gen. records, one Wright family was from Lunenberg Co., Virginia and moved to Georgia (Lincoln, Wilkes).
One in particular, Meredith W., died in 1860 in Pine Level.
If James worked for this family, he may be mentioned in some of the family records.

Another Wright was David F., son of Nathan and Mary Polly Fulton, who died in Pine Level around 1867.

Also, you should search the land records. Perhaps James bought his land from his 'employers'. This would give you another surname to research.

Finally, I would follow the SC/MO mention. It could have been an error on the part of the Census taker, but do not discount it.
Were there any neighbors or other area surnames from Missouri? From SC?

Where is the connection?
Working from the known helps.
Some 'connections' may be circumstantial, but they become targets for additional research in your quest.

Good luck, and please keep us updated.