Frank,
Some of this is off the top of my head (so make sure you double check my facts) but this will head you in the right direction. The Confederate Cherokee organizations can be very complicated due to many re-organizations, varying names used for a unit, and few surviving records.

Maj. Joel Mayes Bryan (fairly frequently written as "Bryant") commanded a cavalry battalion which became the 1st battalion of the 2nd Cherokee Mtd Volunteers. As I understand it, there were quite a few men from Benton County in this battalion.

The name "Cherokee Arkansas Cavalry" may be due to the unit being authorized in Arkansas prior to the Cherokee Treaty with the Confederacy, and might not have anything to do with there being Arkansans in it.

There were a couple of reasons whites along the border joined Indian units. The main one was that the Cherokee couldn't be sent out of their country without their agreement so these men got to stay near home and didn't get transferred east of the Mississippi. These men were also neighbors and business associates with the Southern Cherokee along the Benton County line.

Company E of Bryan's Battalion became Company A of the 2nd Cherokee Mtd Volunteers. The men probably originally enrolled in July 1, 1861 for one year.

2nd Cherokee Mtd Volunteers (Adair's)
Company A, Capt. John Miller

-- Enrolled July 1, 1862 -- Benton Co. Ark.

Seabron S. Pvt
Silas 4th Corporal
William Pvt

Bryan was later promoted to colonel and commanded the "Cherokee Regiment (for Special Service in the Indian Territory)".

Douglas H. Cooper was originally colonel of the 1st Choctaw & Chickasaw Mtd Rifles. He was later put in command of all Indian Troops in the District of the Indian Territory and was promoted to brig gen.

I'd like to know what else you find out about this man.

Ken