Some suggestions, please?

The only books I can suggest are "Blue-Eyed Child of Fortune: The Civil War Letters of Colonel Robert Gould Shaw" edited by Russel Duncan and "The Civil War Notebook of Daniel Chisholm: A Chronicle of Daily Life in the Union Army 1864-1865" edited by W. Springer Menge and J. August Shimrak.

Anyone who has seen the 1989 movie Glory will be familiar with Robert Gould Shaw. "Blue-Eyed Child of Fortune" contains the letters that formed part of the basis for the movie. Because of the movie, Shaw and the 54th Mass. certainly seem to have gained more notoriety than they might normally have had despite being the first authorized all black regiment.

"The Civil War Notebook of Daniel Chisholm" is a real treasure if you can find it. William Springer Menge, on of the book's editors, is descended from Corporal Daniel Chisholm, Company K 116th Pa Volunteers. In fact he's his great-great-grandson. After the war, Chisholm collected the letters he and his brother Alex (also in Co K 116th Pa) sent home. He also somehow managed to get the diaries of Samuel Clear and John Cope, fellow members of the Co K. So you're getting two diaries and the letters of both the Chisholms.