THE ROAD TO DISUNION Volume I: Secessionists at Bay, 1776-1854 By William W. Freehling Oxford. 640 pp. $30

THE HISTORY of the antebellum South retains its endless fascination. Controversy still abounds, both on the subject of slavery and Southern society, and on the political forces which produced, or failed to produce, the Civil War. It has too often seemed as if these two great debates were never going to meet. It is one of the particular merits of William Freehling's massive and challenging new book that it seeks to bring the two together.

The early chapters of The Road to Disunion paint a vivid and variegated picture of Southern society and its peculiar institution. Freehling, who is a professor of history at Johns Hopkins, examines the uneasy balance between the "nurturing" and "coercive" styles of slaveholders in dealing with their slaves and stresses the extent to which white pressure forced slaves into dissimulation and disguise in their own behavior. This ambivalence and ambiguity on both sides of the master-slave relationship exemplify two of the underlying themes of the whole book.

The first is the interplay between what he labels despotism and democracy in Southern society and politics. Aristocratic or elitist principle vied with republican egalitarianism all through the antebellum south. Was class or race to be the key determinant of the Southern social and political structure? Was a conservative planter elite, largely confined to eastern Virginia and South Carolina, to assert and maintain its authority over the rest of the population, both black and white -- or was the color line to dominate everything, with a system of racial slavery underpinning egalitarian republicanism for all whites? In a brilliant passage, Freehling portrays John C. Calhoun and Andrew Jackson as symbolic figures representing these two contending forces.

His second and closely related theme is the diversity within the South itself. Even as late as the 1850s, he says, it would have been a misconception to talk about a single South. If the South existed as a political entity, it was only in the minds of Southern politicians gathered in Washington; at the grass roots, localism, limited horizons and regional diversity prevailed. Freehling traces the widening differences in perspective between the old South of the Atlantic seaboard and the new South, but attaches even greater importance to the distinctions between border states, middle South and lower South. He presents the South as a kind of layer-cake in which slaves and slavery sank steadily and inexorably towards the bottom.

He writes with particular authority and insight about the upper South, where, given the right conditions, a policy of "diffusion" had strong appeal as a means of bringing slavery to an end. Slavery might be drained away (with or without legislative help), as it already had been from the Northern states, in a long process of retreat towards its tropical or sub-tropical home. Free labor would then pave the way for rapid economic progress. For the many Southerners who were unhappy with both permanent slavery and outside attempts to end temporary slavery, diffusion offered a solution which was acceptable, or even convenient. Perhaps the most striking of all Freehling's claims is his insistence that resolute defense of "perpetual" slavery was something which came very late to most of the South. In the mid-1850s, he says, "A huge portion of the most populated South still thought that slavery could and should be ended, always assuming that the right conditions existed."

He shows dazzling analytical skill in his pursuit of this and other themes through the major sectional confrontations of the period. He traces the process by which a relatively small, but active and organized minority was able to exercise leverage on the majority, first in South Carolina, then in the South as a whole, then in obtaining enough Northern support to win crucial votes. With increasing frequency from the mid-1830s, the "politics of loyalty" engendered a competition between the parties to prove which was the stouter champion of the slave South.

Freehling's ability to see familiar events from a fresh perspective often produces exciting results, but they are achieved at a price. The focus on the upper South is a just rebuke to those who speak confidently about "the South" when they really mean the deep South. However, for long stretches of the book, the lower South, apart from South Carolina, seems to have disappeared into a black hole. Mississippi, Alabama, Louisiana and even Georgia are allotted only occasional walk-on parts. Again, skepticism about the existence of a single South is a healthy corrective to bland generalizations; but uniformity is not a prerequisite of a sense of common identity, and the growing feeling that the North was taking control of the American national destiny surely reinforced a distinct and shared sense of Southernness.

None of these reservations detracts seriously from the value of what is, or ought to be, one of the most important books on Southern history for many years. If it fails to win the attention and acclaim which it deserves, there will be only one person to blame -- and, paradoxically, that is Freehling himself. The message emerging from his formidable scholarship is in danger of being devalued by the style of its presentation. On the evidence of his earlier work, he possesses a perfectly good, clear prose style. Sadly, in his magnum opus he has chosen to abandon it for a style too often reminiscent of the more lurid kind of popular fiction. It is almost as if the work of a major Southern historian such as David Potter or C. Vann Woodward had been rewritten in the style of Mickey Spillane. SOME OF the lapses may be due to careless editing. But there is obviously deliberate intent behind the purple passages and the straining after dramatic effect, the overstretched figures of speech, and, worst of all, the constant resort to slang and sloppy language. What do we really learn from the statement that "Exotic cultures, like flamboyant lovers, may appear simple at first"? John C. Calhoun is referred to repeatedly as "Mr. Nullifier" or "Mr. South Carolina," friends become "pals" and Howell Cobb is always introduced as "Fatty Cobb." On successive pages, the reader learns that "no cloth was broad enough to cover Governor Quitman's derriere," and that "Henry Foote had no trouble making his zig square with his zag . . ."

Such language is unworthy of any serious work of history, and certainly of a book as powerful, challenging and important as this one. Freehling promises a second volume covering the crisis years from 1854 to 1861. He will have a lot of work to do, in order to show how so much of his heterogeneous South of many Souths, with its small minority of champions of perpetual slavery, moved to secession and disunion in those seven years. However, he is an immensely gifted historian who will no doubt prove himself equal to that task. If, perhaps with the help of a ruthless editor, he can apply to his stylistic excesses the endearing habit, revealed in several footnotes here, of condemning his own past errors, he will surely present us with a truly remarkable book.

Peter J. Parish is director and professor of American History at the Institute of United States Studies, the University of London. He is the author of "The American Civil War" and "Slavery: History and Historians."