This is all I could find:

John McGrath

Residence was not listed; 30 years old.

Enlisted as a Private (date unknown).

He was listed as:
* POW 4/16/1865 (place not stated)
* Wounded 4/16/1865 (place not stated) (Severe wound in left leg, amputated)

He also had service in:
"I" Co. US Army 4th LA Batty C

Sources used by Historical Data Systems, Inc.:

- Index to Compiled Military Service Records
- The Medical and Surgical History of the Civil War
(c) Historical Data Systems, Inc. @ www.civilwardata.com