The internal debate between moderates and secessionists, played out at a special convention in Richmond, Va., that began in February 1861, provides Mr. Lankford with his best material. For long weeks moderates held the balance of power, resisting the impassioned oratory and threats of violence from rabid secessionists. Virginia’s struggle was repeated throughout the upper South, which held fast to the Union for longer than anyone had a right to expect, even after shots were fired at Fort Sumter on April 12, an event that produced “anguished indecision” rather than immediate rupture.  One Tennessean advocated a border-state confederacy as a way to preserve “strict neutrality between the madmen of the sections.” This option seems absurd in hindsight, but at the time, Mr. Lankford argues, it did not. A mere seven votes out of 141 at the Virginia convention pushed the state to secede rather than hold a statewide referendum on the issue. What if the vote had gone the other way? In the intervening weeks before a referendum, Mr. Lankford writes, “passions might have cooled, and even if they did not, the unionists would have taken heart from defeating the radicals.”  Some of Mr. Lankford’s what-ifs seem more like who-cares? Small decisions that if changed might have led to medium-size consequences read like niggling footnotes to a story that does not lack for dramatic sweep. But there are plenty of intriguing midrange possibilities to keep Mr. Lankford’s historical parlor game alive, especially in Maryland. If Gov. Thomas Hicks had given in to the demands of Democrats and recalled the general assembly in April, after Lincoln issued a proclamation calling for the states to raise militias for war against the South, Maryland would probably have voted to secede from the Union.  Perhaps just as fateful were the unintended consequences of Hicks’s decision to burn railroad bridges on the two lines that would carry northern militias south to Washington. By making a wide circle around Baltimore, the troops avoided inflaming a city already on the brink of revolt and kept Maryland, however tenuously, in the Union.  Almost any outcome seemed possible in spring 1861. One of the virtues of Mr. Lankford’s approach is to put readers in the minds of ordinary Americans trying to make sense of volatile events. War did not seem inevitable: most Americans had lived with sectional conflict and inflammatory political talk for most of their lives. The North-South split was never clean. And consequences were never clear. In the euphoria after Virginia’s vote for secession, Confederate zealots foresaw a new economic order in which foreign trade gravitated to Southern ports, and cities like New York withered away.  “A gilded corpse lies on the shores of Manhattan,” The Richmond Examiner exulted, as news spread of Virginia’s defection.  Mr. Lankford proposes a final what-if. What if the eight states of the upper South had all gone the same way? If they had all seceded, he argues, the North would probably not have been able to defeat the Confederacy. If they had all stayed, the war would have been over very quickly.  “The tragedy for the country was that the upper South split roughly down the middle,” he writes, the very outcome guaranteed to prolong the conflict as long as possible.  Of course, no one knew this, or anything else, for that matter. As one newspaper writer put it on April 19, 1861, “Three months ago a person would have been regarded as a madman who had predicted the present state of affairs.”  A version of this review appears in print on , on Page E9 of the New York edition with the headline: The Many Roads Not Taken on the Way to Civil War. Today's Paper|Subscribe
Nelson D. Lankford unravels the events that led to war in 1861, disturbing the march of history with a series of provocative what-ifs.