Undeniably the most complete work in print about the regiment is Jess N. McLean Sr.’s so-called “Official Records.” They’re official insofar as they are muster rolls and orders and after-action reports. The book also contains excerpts from private diaries and letters, many of which are available in various archives in Mississippi and elsewhere. I’ll be quoting from them from time to time.
Mr. McLean spent years gathering the rosters and individual records and also some photographs, diaries, and letters which are not available anywhere else. His book is well worth owning. It suffers only from repetition and could use a good editor and an index. But, for the present, it is the very best source available for anyone with more than a passing interest in the Thirteenth Mississippi. I recommend it wholeheartedly.
UPDATE: On Oct. 23, Mr. McLean announced that a new version of the book that is less repetitious and considerably cheaper than the old one is now available.