This is a case of mistaken identity. Hardin didn't enroll in the 3rd Alabama Cavalry, but the 3rd Confederate Cavalry. The regiment included a number of companies from the northeast corner of Alabama, the northwest corner of Georgia, and adjecent counties in Tennessee. Hardin's command was included in the surrender of April 26, 1865, his parole being dated Hillsboro NC, May 3, 1865.
Dawson is a post office established in DeKalb County in 1887. It's southwest of Lebanon in Wills Valley and served as the county seat from 1840 until 1876.
Copies of Hardin's actual service file and pension application are availbale here.