You might find out something re his switching sides by obtaining his pension papers. You can procure them through the service noted in the Red enclosed box above.

Arkansas Confederate Pensions

Surname: Dickerson
Given Name: Nathan B.
Application Number: 19793
Widow Surname:
Widow Given Name:
Company: H
Regiment: 26
State Served From: Arkansas
Division: Infantry
Pension County: Johnson
Death Date:
Application Year: 1903
Widow Death Date:
Comments: approved

http://arkansashistory.arkansas.com/search/detail.asp?sec=ConfPension&id=10969