Ms. Kirk,

One reference you may want to check first is "1864 Census for Re-Organizing the Georgia Militia" by Nancy J. Cornell. This has the counties broke down by Senatorial Districts (in more modern terms; State Election Districts). If you want to know the exact boundaries of these districts you will likely have to contact the Georgia State Library and Archive in Morrow, Georgia for assistance. The GSLA will also have any records of his Militia service if it exists.

I hope this helps.

Respectfully,

Gerald D. Hodge, Jr.
War Between the States Historian
Historian: 39th Georgia Volunteer Infantry Regiment
http://39thgavolinfrgt.homestead.com/39thHomepage.html