Sir,

1. Yes, check the spelling again.

2. There is not a 31st Tennessee Cavalry for the Federals or Confederates.

3. There is a 31st Tennessee Infantry for the Confederates.

4. I could not find a E. Ettar or derivative spelling.

5. Check the census in the decade prior to his death for a proper spelling and location of birth.

6. There are some Etter's that apply for pensions in the state of Tennessee but none with the name or middle initial of E. You may want to check Indigent Soldier's and Widow's Pensions in the state of Virginia. They may have applied in Virginia.

7. Check the origin (original country or region) of the name and then look for variations of the phonetic spelling.

The list I check are from the reference below.
Reference used: "Tennesseans in the Civil War, Volumes I & II."

Please let me know if you have any questions.

Respectfully,

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