Two years ago I would have been less knowledgeable also except for taking the time to dig a little deeper.
We found our best sources in the OR itself, Confederate Veteran Magazine Articles and letters to the editors of the magazine. Gen. S.D. Lee wrote an excellent post war article about the battle. Especially interesting were letters from Pvt. Leavitt of the 41st Miss. describing the desperate fighting at the breastworks by both Confederate and Federal forces, another by Simon Mayer of Natchez, Miss. of Sharp's Brigade. "A Carolinian Goes to War" by Gen. Arthur Manigault also in Johnson's Division of Lee's Corps. gives a good description of the fight and it's aftermath.
Joe Ashley [One of our Message Board Author]in his recent book "Oh for Dixie" also describes the battle from the viewpoint of the 30th Miss. of Brantley's Brigade also of Johnson's division and their participation.
I am sure that there are also personal recollections by men in the federal units also published after the war or for reunions of the GAR; I have just not been able to stop my research on the 7th Miss. long enough for that side trip. Hopefully someone else can fill in the gaps for us all.