U.S. Civil War Soldier Records and Profiles
Name: James H Cassidy
Residence: Chatham County, Georgia
Rank at enlistment: Private
State Served: Georgia
Survived the War?: No
Service Record: Enlisted in Company G, Georgia 1st Infantry Regiment.
Mustered out [DIED]on 12 Aug 1863 at Morris Island, SC.

Sources: Roster of Confederate Soldiers of Georgia 1861-1865

Battles Fought
Fought on 8 Apr 1862 at Savannah, GA.
Fought on 10 Apr 1862 at Fort Pulaski, GA.
Fought on 11 Apr 1862 at Fort Pulaski, GA.
Fought on 3 Dec 1862 at Murfreesboro, TN.
Fought on 12 Aug 1863 at Morris Island, SC.

It seems to be just a variation in the spelling of the name. I am not finding any other James H. Cassady/Casaday/Casssidy in any of the other 1st Ga Regiments.