In 1998 a book was published called The Slaughter: An American Atrocity by Carroll Case. It alleged that in June of 1943 at an Army base in Mississippi 1200 black soldiers were massacred by white soldiers, and the entire incident was covered up. The allegation prompted investigations and a documentary on the History channel, which was summarized as follows by the Philadelphia Citypaper:
The hour-long program explores allegations that, upon first read, seem ridiculous — especially a charge that 1,200 African-American combat troops were killed by white soldiers in a single massacre at Camp Van Dorn in the isolated town of Centreville, MS, and that a subsequent cover-up has gone on for almost 60 years. That claim was made in a 1998 book, The Slaughter: An American Atrocity. Former Mississippi banker Carroll Case pursued the claim for years after one of his employees told Case he had participated in the killing. William "Bill" Martzall, who joined the military police of the 63rd Division out of his home in Dillsburg, PA, first told Case this tale in the 1980s. Martzall has since died. The U.S. Army categorically denies Martzall’s version and claims he could not have even been in Camp Van Dorn during the period he described to Case.
As the Citypaper goes on to document there could be no doubt that the situation at Camp Van Dorn was terrible and there certainly was violence.
Letters in the National Archive and in NAACP files describe the events that ensued. "We are catching hell here," a member of the 364th wrote. "Two of our men have been kill [sic] and we have only been in this camp for six days. Something worse is going to happen soon." "There have been about 20 or 25 Negros [sic] hurt and kild [sic]," another white soldier wrote. "They [sic] have been 5 or ten shot right through the head … and we are going to give them hell when they come around us."
The 364th’s Morning Reports, a kind of company-by-company daily attendance sheet, note dozens of soldiers as AWOL following the Walker shooting and its aftermath. Files in the National Archives trace some who made their way north, seeking from their local induction boards asylum from what they called a life-threatening situation.
Following reports of the Walker killing and subsequent riots, black leaders sought to find out what happened. In a June 17, 1943, memo President Franklin D. Roosevelt asked the Secretary of War Henry Stimson to prepare a response to a telegram from Edgar J. Brown, director of the National Negro Council. Brown asked that Bishop David Henry Sims, leader of the African Methodist Episcopal Church in Philadelphia, be authorized to investigate conditions of black soldiers at southern military bases, "especially Camp Van Dorn."
Brown’s request was politely declined. A letter prepared by Stimson for the president’s signature concluded: "You may be assured that every effort is being made to safeguard interests of Negroes in the Army."
Whatever happened to the 364th in the summer of ’43, in December the regiment’s remaining men were relocated to a far-off camp in the Aleutian Islands. It was then that their personnel roster began to show signs of hemorrhage. Records show that between 800 and 1,000 of the 3,000 men left the 364th before the war’s end. In other words, from June 1943 until Japan’s surrender, about one soldier’s name per day disappeared from the 364th’s roster.
But when you get right down to it the only real evidence of the alleged mass killing is Case's account of being told about the incident by one person, now dead. In the ten years since this was first brought up has any other evidence of a massacre been found?
Edited with new information
I got a copy of the book The Slaughter: An American Atrocity and had a chance to read the source of the claim. The odd thing is that the factual part of the book is only about 50 pages, including several pages of transcripts and reproductions of official documents. The rest of the book is a fictional account of a reporter investigating a fictional hate crime vaguely based on the author's own experiences. It struck me as an odd approach to such a serious accusation.
Carroll Case's primary source is William "Bill" Martzall, who worked with Case. One day years ago, Case says, Martzall confessed his role in a massacre at Camp Van Dorn. Though really, the word "confessed" may be a little strong. As Case relates it, Martzall's story sounds like a race-baiting fantasy. Martzall's story starts off fairly factual, talking about how the 364th had a bad reputation from events that happened in Phoenix. Martzall says that the population of Centerville was so concerned about this influx of troublesome black soldiers (I should note that the whole account only uses the n-word to refer to them) that a local sheriff decided to kill one just to teach the others a lesson. This would appear to refer to the death of William Walker, which I'll address separately. After this, however, the story gets suspect. Martzall then says there was supposed to be a July 4th dance on base, but the black soldiers disrupted the festivities before they could start. The final straw occurred when black soldiers attacked a pregnant white woman and ripped the baby from her womb, "stomping it to jelly." That night Martzall says he was assigned to a machine gun squad that gathered the 364th into an open area on the edge of the base and killed "hundreds, maybe a thousand" black soldiers. The bodies were loaded into a train and somehow disposed of.
Obviously, if a pregnant woman and an unborn child were killed in such a gruesome manner it would be big news, but no such death is associated with the 364th. I'm pretty sure that the whole later part of Martzall's story is just a horrible racist fantasy.
The story in no way specifies 1200 or 1227 dead. None of Case's sources would have any way of knowing how many dead there were, and it was not a case of simple subtraction as suggested in the comments. The math doesn't work out. I'd be interested to know where the number comes from.
Case also presents what he says is the "smoking gun," a memo from a Major General Virgil Peterson commenting on the plan of a General McNair to discipline the 364th. We don't know what McNair's plan was, but Case assumes it must have been the massacre. I would point out that while Peterson's memo doesn't say exactly what McNair's plan is, it doesn't sound from his responses that it's anything extraordinary. For example, Peterson doesn't think the people of Centerville should be given a veto on the black soldiers' access to town. I'm not sure how that fits into a plan to kill a large number of those soldiers.
None of this is not to say that bad things weren't going on at Camp Van Dorn. The William Walker killing, in particular, sounds like premeditated murder even in the official documents trying downplay it. Walker, on leave, was confronted by two armed MPs, a town sheriff, and an unspecified number of shotgun-toting men acting as a posse, for the "crime" of missing a button on his uniform. The MPs claimed that even though he was faced with what I assume must have been at least seven heavily armed men Walker started a fight and the sheriff had no choice but to shoot him. I can see why the NAACP would have taken an interest in that.