Well, Griffin's Battalion was definitely in the Battle of Galveston. (See page 116 of my Battle on the Bay book). I don't have any information though about the actual names of men who were present in the battle. But they were certainly in the thick of things, making a wading charge on Kuhn's Wharf under the direction of Colonel J.J. Cook. There is a photo in my book of that wharf as it looked in 1861. It was at the foot of 18th street. Even Colonel Cook did not know the names of the men who made that charge as he expressed in a letter after the battle.But he said "Braver men I never desire to behold." High tribute to his men, which probably included your ancestor.