Unfortunately, you will find not much more than what you already have, I have added a couple of items which weren't in your records.
George Martin
John F. Johnson
Residence was not listed; 29 years old.
Enlisted on 6/18/1861 at Washington County, VA as a Private.
On 6/18/1861 he mustered into "I" Co. VA 48th Infantry
(date and method of discharge not given)
He was listed as:
* On rolls 10/15/1861 (place not stated)
* Hospitalized 10/31/1861 (place not stated)
* Hospitalized 1/2/1862 Charlottesville, VA with Rheumatism
* Returned 3/10/1862 (place not stated)
* Paroled 6/1/1862 Winchester, VA age 29, 5 ft. 7 inches
* POW 6/8/1862 Cross Keys, VA
* Confined 6/9/1862 Steamer "Coatzacoalcos"
Enrolled June 18,1861 at Washington, Co.
Mustered into service July 3, 1861 at Abingdon, age 29