26th Maine was under Colonel Nathaniel H. Hubbard IIRC, and served in the 3rd or 4th Division, 19th Corps at Port Hudson, in the Left Wing.
28th Maine was in two battalions -- one battalion fought at Donaldsonville under Maj. Joseph D. Bullen, while the other served at Port Hudson under Colonel Ephraim Woodman. Many 28th Maine men reenlisted in the 2nd Maine Cavalry.