Archaeological discoveries

How can I find out if their was a Plantation owned by John P. Robertson in Arkansas or North Carolina the early found this person many slaves. And where it located?

Arkansas

- There is no evidence of a plantation owned by John P. Robertson in Arkansas during the early 1800s.

North Carolina

- There is no evidence of a plantation owned by John P. Robertson in North Carolina during the early 1800s.

Alabama

- John P. Robertson did own and operated a plantation in Montgomery County Alabama. In 1840 he owned 200 slaves. There is no information found so far on the name or location of his plantation.