Try the Records of the Freedmen's Bureau, recently available on the Net.Also check the Tiger Map Service Gazeteer for the site of Boatner, La., 20 mi. WSW of Monroe.
Boatners oviously moved west after the Civil War from Catahouls Parish and SW from Morehouse Parish, where they had been prominent as landowners, jurists (several judges) and legislators. My greatgrandfater, Charles Jahleal Boatner, represented the district in four sessions of the US Congress at the end of the century. He might have been on Cleveland's cabinet if he had his wife,Fannie Spencer (?) Mayo, had not been sick of Washington and longed for New Orleans.
Needless to say, I wish you luck and hope we can keep in touch.