ON JUNE 20, 1864, the Union Army of the Potomac, under Gen. George G. Meade, was entrenched before the heavily manned fortifications of the city of Petersburg. It was a classic stalemate; in an almost desperate move to end it the men of the 48th Pennsylvania Volunteers, miners in civilian life, proposed to construct the longest military tunnel in history, and so undermine the Confederate trenches.

The idea was supported by Gen. A. E. Burnside, commanding the Ninth Corps, who developed a plan of battle which began with the explosion of the mine followed by a disciplined attack by the black troops of his Fourth Division, who were being specially trained for the assault. The plan was subtly opposed by Meade and his staff, who hampered the mining operations by withholding equipment and material, reduced the amount of explosive for the mine by a full third, and who, for reasons of politics and prejudice, replaced the well-trained and highly motivated black troops with exhausted and demoralized whites. Despite the fact that the mine was successfully exploded -- creating the massive crater of this book's title -- the attack itself was a fiasco. The Congressional Committee on the Conduct of the War later concluded that:

"The cause of the disastrous result of the 30th of July last is mainly attributable to the fact that the plans and suggestions of the general who had devoted his attention for so long a time to the project . . . should have been so entirely disregarded by a general who had evinced no faith in the successful prosecution of the work."

Richard Slotkin is a gifted historian. His first book, Regeneration Through Violence: The Mythology of the American Frontier, 1600-1860, was judged the best book of 1973 by the American Historical Association and was nominated for the National Book Award. But in writing The Crater he has chosen to write history as a novel. In doing so he has ventured onto dangerous terrain.

Novels of this type -- personifications, in a sense, of historical events -- are, in some ways easy to write, for the historical framework does a great deal of the author's work for him. He need not explain why the events are significant; history has done that. He need not construct elaborate ruses to bring disparate characters together, for events force them together, giving rise to powerful ironies -- as here, where miners, ostensibly at war, find themselves not only pursuing their peacetime trade, but doing it under precisely the same men, now officers and noncommissioned officers, who were their bosses and foremen in civilian life. Finally, he need not invent what happened next, or worry about his audience rejecting it as implausible; he can concern himself with why and how; the what, where, when, and most of the who are given him. And yet the form is a dangerous one, for the audience cannot be counted on to know the true facts, and so the writer must carefully adhere to the old prescription to both delight and instruct, for should he fail to do both sufficiently well, he will fail to do either.

Slotkin is a beginner as a novelist, and so The Crater is not as tight a novel as it should be. Slotkin is given to excesses. He makes up too much; he has "invented or significantly altered" documentary materials, which weakens the natural ironies, since the reader must forever wonder what is fact and what is not. He has an impressive knowledge of fictional techniques, but he insists on using them all. He is gifted at characterization, but he errs by characterizing everything that moves. These flaws are most apparent at the opening of the book, when Abraham Lincoln's visit to the front provides Slotkin with a weak excuse for a lengthy stream-of-consciousness section which, while beautifully written, is totally unjustified by Lincoln's importance, as a character, to the whole of the book. In addition there are simply too many characters here for anybody to keep track of (including Slotkin, evidently; at one point he forces us to experience the death of somebody of whom, and from a unit of which, we have never before heard). And finally, Slotkin in his last chapter carries the story far beyond the natural bounds the Battle of the Crater provides.

But while he does some things wrong, Slotkin does most things brilliantly. He writes beautifully, capturing the smell and feel of war in crisp phrases, precise and gently offered images: "Shadows carried him to the ambulance wagon. His arm began to toll like a bell." The characterizations -- even the unnecessary ones -- are superb; Slotkin brings to this novel -- and, one hopes, to future ones -- the very rare ability to comprehend events both in terms of the grand sweep of history and in terms of the beat of human hearts. Thus he captures the contradictory emotions and complex motivations of black troopers and of the whites who led them, of staff officers fearing for their futures, of generals who contend more spiritedly with each other than with the enemy, presenting them without quick judgment, but with slow understanding. His sense of irony is unfailing, and reaches its height in the chapter entitled "Diversion," in which the events of a diversionary strike to the north are skillfully juxtaposed with scenes of the black troops demonstrating their readiness by half-playing at assaulting a troop of taunting whites, and with a minstrel show in Washington. In this sequence, which just precedes the battle, Slotkin provides a complex metaphor not only for the imminent struggle, but for the war itself.

Because of Slotkin's basic soundness as a writer and the undeniable power of the form, The Crater does not merely survive its flaws; it overpowers them. To read it is not merely to be instructed about the battle or the war, not merely to be delighted by good writing and revealing characterization, but to witness a well-planned assault in which fact and fiction join forces to strom the high ground of truth.