Thanks for all the information. The Rebel Captain Bowman I seek accompanied Hildebrand on that particular patrol to wreak vengeance on a particular militiaman for murdering his brother--Hildebrand said this Yank murdered the brother to get a particular fine horse the brother rode. I don't know if the Captain Bowman I named is the man or not. There is not much to work with on this story, and I'm tempted to drop it. We assume Hildebrand remembered the captain's name correctly the three years before he wrote his memoir.
Bruce