After the surrender at Port Hudson, the original Co. H (from Clark County) did not rejoin the 23rd Arkansas in northeast Arkansas. It was replaced by a new Co. H (from Craighead County). The members of the original Co. H returned to Clark County, where some of them reentered the service in other regiments.
So, there is no record of subsequent service of John H. Holcomb. There is a document erroneously included in his Compiled Service Record, indicating that he served as a contract surgeon at Camden, Arkansas. The document is in the name of "J. M. Holcombe" and in fact is the record of Dr. James M. Holcombe, a physician from Union County, Arkansas, who was appointed Surgeon, PACS, on February 1, 1862, and appears on an undated consolidated list of staff officers of the District of Arkansas, with the notation: "surgeon, to examine conscripts at Camden, Arkansas". As I said, this record is erroneously filed with your John H. Holcomb's compiled service record.