Intelligence in War: The Value--And Limitations--Of What the Military Can Learn About the Enemy (12 page)

The other point of light was the existence of a Confederate diversionary force, poised to unsettle both McClellan and Lincoln, though in different ways. McClellan could be thrown into anxiety by any move threatening to deprive him of the reinforcements he craved. Lincoln, more tellingly, was prone to alarm at any prospect of a Confederate advance against Washington. The Confederates around Richmond lacked the capacity to level either threat. General Thomas Jackson, “Stonewall,” far away though his small army lay in the Shenandoah Valley, was equipped, equally by location and capability, to organise both. Any thrust northward he might make would menace Washington, which Lincoln increasingly believed had been selfishly stripped of troops by McClellan to bolster his Peninsula adventure. Such a thrust would simultaneously lessen the likelihood of Lincoln’s agreement to the redeployment of the covering armies of Banks and McDowell from the Shenandoah Valley vicinity towards McClellan at Richmond. Stonewall Jackson, in the spring of 1862, suddenly found himself in a “swing” position, capable of altering the course of the war, if he handled his force correctly, with decisive effect.

The Shenandoah Valley was a strategic corridor, which worked as a critical anomaly in the military geography of the Civil War. The heartland of the Confederacy, as originally constituted, between the sea, the Mississippi and the mountains, was virtually impenetrable. McClellan had cracked the carapace by finding a maritime point of entry on the Virginian Peninsula, but to enlarge the breach he would need to show a determination and single-mindedness his contemporaries of the West Point class of 1846 had good reason to doubt he possessed. Otherwise, as long as the lower course of the Mississippi was held, there was only one other way in: down the Shenandoah. The Valley is the easternmost feature of the central Appalachian chain. Its southern exits lead into the plains of Virginia, the Carolinas and Georgia, its northern exits into Maryland, Pennsylvania and towards the outskirts of Washington. In the circumstances of the Civil War, it could be used offensively or defensively. Theoretically, the North could use it as a way into the Confederate heartland; in practice, the lack of a north–south railroad within the Valley made that manoeuvre logistically too difficult to undertake, though it was one against which the South always had to be on guard. On the other hand, the South could much more easily use the upper mouth of the Valley as a sally port from which to surprise Northern armies near their major cities. During the course of the war, it was the South which better exploited the strategic potentialities of the Valley and never more so than in the spring of 1862.

There is a large and small strategic geography of the Valley. The large is that of a corridor leading either in or out of what between 1861 and 1865 was the Confederacy; the small is that of its internal features which, if correctly understood, can be put to decisive military use. About 120 miles long and 30 wide, from the headwaters of the South River to the confluence of the Shenandoah and Potomac at Harper’s Ferry, and from the crest of the Alleghenies to that of the Blue Ridge Mountains, the Valley is an enclosed environment of what, in 1862, was rich, cleared farming land. Down the centre, however, runs a dividing ridge, the Massanutten Mountain, which itself divides the Shenandoah River into a North and South Fork. Joined near Front Royal, the forks become the Shenandoah proper, to run northward for forty miles to enter the Potomac at Harper’s Ferry. The tail of the South Fork separates at Port Republic into three minor streams, the North, Middle and South rivers.

Many rivers mean many bridges, and there were, in 1862, at least twelve of military significance, providing crossings at the Valley’s principal townships and villages; like others of that period in the American settlement of the interior, most were wooden and easily burnt. Besides bridges, there were other passages of strategic significance, fords here and there, but also gaps in the surrounding mountain chains. Those leading out into West Virginia, dominated by the North, were few and of lesser military importance. Those giving on to the lowlands of Virginia proper were more numerous—there were eleven in all—and of altogether greater significance, since they provided a Confederate army inside the Valley with the means to dodge back and forth. Equally important was the gap through the central Massanutten ridge between New Market and Luray and the east–west links around the Massanutten’s headlands at Front Royal and Port Republic.

The Valley’s internal geography determined its road network. It was better west of the Massanutten, where the Valley Pike—an all-weather macadamised road of impacted gravel—led from Williamsport on the Potomac, via Winchester, Strasburg, New Market and Harrisonburg, to Staunton, between the South and Middle Rivers. East of the Massanutten, an inferior road ran from Front Royal through Luray to Port Republic and eventually to a junction with the Valley Pike at Staunton.
⁵

Few, if any, in the Northern armies understood the Valley’s geography. There were two reasons for that. The first was that in peacetime, the Valley’s communications with the outside world had been almost exclusively by river, up and down the Shenandoah and its branches to Harper’s Ferry; so important were the waterways that Valley people described the northward passage to the confluence as going “down,” the southward as “up.” The North therefore knew the Valley only as a river system, and then at its external points of connection. The second was that there were virtually no Valley maps. That was a prevailing condition of warmaking between the Union and the Confederacy. The Federal government had, before 1861, invested considerable sums in mapping the United States’ coasts; one of the branches of the United States Army, the principal instrument of the government’s internal administration, was a Corps of Topographical Engineers. It had also sponsored a major exploration of the west, as a support to its sponsorship of settlement beyond the Mississippi. It had done nothing similar in the old Thirteen Colonies or the eastern states founded since 1782. The result was that the generals of the Civil War embarked on their operations with wholly inadequate cartographic resources.

No accurate military maps existed. [The Union] General Henry W. Halleck was running a campaign in the western theatre in 1862 with maps he got from a book store. With frenetic haste, the general set topographical officers and civilian experts to work, making maps, but the resulting charts were generally incorrect. Benjamin H. Latrobe, the civil engineer, drew a map for a general going into Western Virginia, but the best he could promise was that it would not
mislead
the expedition. General George B. McClellan had elaborate maps prepared for his Virginian expedition of 1862 and found to his dismay when he arrived on the scene that they were unreliable; “the roads are wrong,” he wailed. Not until 1863 did the [Northern] Army of the Potomac have an accurate map of northern Virginia, its theatre of operations.
⁶

At the root of the trouble lay the cartographic backwardness of the United States. That might be thought understandable: the United States was an enormous country, still largely unsettled, by no means completely explored and without a central mapping agency; the army had its Corps of Topographical Engineers, the navy a Hydrographic Office and the federal government a Coast Survey, but they were all tiny.
⁷
The basis for accurate survey, a comprehensive triangulation of the land mass, was absent. Yet it had been done elsewhere. The British Isles had been triangulated and a comprehensive series of high-quality maps published, at one inch to the mile, by the Ordnance Survey, beginning in 1791; a small undertaking, certainly, but magnificently accomplished. Impressive by any standards was the work of the Survey of India; India, though smaller than the United States, is topographically even more complex, because of the height and extent of the Himalayan chain. Beginning in 1800, the Survey, under the direction of a succession of military engineers, had embarked on a complete triangulation. Triangulation, which supplies measured distances between a series of intervisible points, allowing for the curvature of the earth, provides the grid from which accurate maps can subsequently be drawn. It was largely complete by 1830 but was subsequently extended and corrected, notably under the leadership of Sir George Everest, after whom the world’s highest mountain is named. His team of surveyors and trigonometricians was never more than a few hundred strong but, largely inspired by the challenge of the enterprise itself, they succeeded within seventy years in producing a complete series of accurate maps of a sub-continent equivalent in size to that of the United States west of the Mississippi.
⁸

By 1861, no triangulation of the United States had been undertaken. It was a strange blind spot in the American attitude to their magnificent country. George Washington was by training a surveyor; so was Abraham Lincoln. Thomas Jefferson, most intellectual of presidents, had a passionate interest in exploration and sponsored the Lewis and Clark trans-continental expedition to the north-west in 1804. He made it clear, however, that its purpose was to discover “the most direct and practicable water communication across this continent . . . for commerce.” Route-finding, first for commerce, then for settlement, then railroads, defined American official interest in continental geography. In 1836 President Andrew Jackson sent a U.S. Exploring Expedition, under Lieutenant Charles Wilkes, to investigate the territory of the United States, but it was seaborne and largely committed to investigating the coasts. The earliest major exploration of the interior was authorised in furtherance of the Pacific Railroad Act of 1853, “to Ascertain the most Practical and Economical Route for a Railroad from the Mississippi River to the Pacific Ocean,” which designated five possible lines, all to be surveyed by the army’s Corps of Topographical Engineers. The routes were mapped, but no comprehensive and accurate survey of the United States resulted. That lay in the future.
⁹

There were, of course, already many local maps of the United States, made necessary by the need to define sub-division of the land for farming under the pressure of immigration and westward expansion. Flatness, so characteristic of the American landscape in the Midwest east of the Mississippi and in the Great Plains beyond, allowed accurate delineation of property boundaries by reference to astronomical observations of latitude early on and longitude, by telegraphic time calculation, by the 1860s. Such mapping, however, was piecemeal. Without comprehensive triangulation, local maps did not accurately connect with one another, nor did they, in the hilly areas of the Appalachian chain and in the coastal regions to the east, usefully depict height, or contour. No wonder that, as late as 1864, Colonel Orlando Poe, General William Sherman’s chief engineer, should complain that the maps of North Carolina he was able to find “vie with each other in inaccuracy.”
¹⁰
Traditionally maps had been military secrets, those of one’s own country to be kept from the enemy, those of his to be made with stealth; with reason, for mapmaking was rightly regarded as espionage. Frederick the Great in 1742 established a secret map room (
Plankammer
) in his palace at Potsdam, which contained maps both of Prussia and of surrounding territories, such as that of Silesia, which he had made before his invasion that caused the Seven Years War.
¹¹
The Survey of India ran what was effectively a widespread espionage network in the countries bordering the Indian empire to the north, including Tibet, Nepal, Afghanistan, China and Russian Central Asia, staffed by Indians who were trained to measure distances by counting their steps on strings of prayer beads. Hurree Chunder Mookerjee, one of Kipling’s most delightful creations in the cast of characters in
Kim,
was such an agent, but he had his models in real life. The most famous, as he became when allowed to emerge from obscurity, was Nain Singh, known as “the Pundit” or sage, who between 1864 and 1875 twice visited Lhasa, then a closed city, covered 1,200 miles of previously unsurveyed country and followed the course of the great Tsangpo River for 600 miles from its source. On retirement from the Survey of India, he was rewarded with a grant of land, the rank of Commander of the Order of the Indian Empire and the gold medal of the Royal Geographical Society, at which he lectured to rapt attention when he visited England.
¹²
He was perhaps lucky to survive to retiring age. Nepal, when threatened with invasion by the East India Company in 1814, carefully disguised the mouth of the main road leading into the country and the government threatened death for its betrayal.
¹³

The South, threatened with invasion in 1861, could not disguise the mouth of its internal roads, since they connected with those of the North. Thereafter, however, their course was often poorly reproduced on such maps as were available to Northern generals, or inaccurately represented, or not marked at all. Local knowledge often counted far more than the plates in a shoddy bookshop atlas. It was much more readily available, inside the South, to Confederate defenders than Union invaders. Without it, confusions accumulated. Even quite good maps could be out of date, while there was no guarantee that the mapmaker’s choice of place-name was that used by locals. “Cold Harbor, Virginia” (the site of one of General Ulysses Grant’s battles in 1864) “was sometimes called Coal Harbor, and there was also a New Cold Harbor and a ‘burned’ Cold Harbor. Burned Coal Harbor was known by the locals as Old Cold Harbor. Many of the roads were known by one of two names: the Market or River Road; the Williamsburg or Seven Mile Road; the Quaker or Willis Church Road. To add to the confusion, there were sometimes other nearby roads with the same or similar names that ran in completely different directions.”
¹⁴

Locals knew; invaders did not. That was to confer an almost consistent advantage on the South, which, for most of the war, was campaigning within its own territory and defending it very often with locally raised troops. That was particularly the case in the Shenandoah Valley in 1862. Stonewall Jackson, the commander of the Valley Army, was a Valley man. After retiring from the regular army, he had become a professor at the Virginia Military Institute, the private military academy at Lexington at the Valley’s southern end. Many in the Valley Army were Valley men, particularly those of the Stonewall Brigade, which had won its name at the First Battle of Bull Run, and of the Rockbridge Artillery, largely recruited from students at Washington College, also in Lexington. Perhaps the most important Valley man in the Valley Army, however, was a civilian, Jedediah Hotchkiss. A schoolmaster, he had set up his own school at Staunton in 1847. It flourished and, though a New Yorker, he stayed. He also began to pursue the hobby of mapmaking. General Robert E. Lee employed him as a mapmaker in his campaign in the Alleghenies, west of the Valley, in 1861. In 1862, home after illness, he attached himself to the Valley Army and was introduced to Jackson. The latter was impressed by his local knowledge and on 26 March added him, though he was a civilian and would remain so, to his staff. His first order to Hotchkiss was “I want you to make me a map of the Valley from Harper’s Ferry to Lexington, showing all the points of defense and offense between those points.”
¹⁵