The American Civil War was a maritime war, despite the large armies engaged and the great battles fought on land. It was a maritime war because the geography of the theater of operations, the southeastern portion of the present United States, made it so. There were no Trafalgars, for its decisive naval actions were not fought on the high seas. The struggle was for control of the coastal and inland waters on which the economic life of the South depended and from which the conquest of her territory had to be undertaken.
The Southern leaders who took their section into war in 1861 believed that independence was certain because they thought the South could not be invaded successfully. European statesmen were of the same opinion. These men were wrong because they reasoned only in terms of a continental war and of land campaigns. Instead, the struggle between the sections became a maritime war in which sea power determined its nature and settled its issues.
The American Civil War had been over less than a generation when one of its participants, Captain Alfred Thayer Mahan, U. S. Navy, published The Influence of Sea Power on History, 1665-1783. This manuscript, which the discouraged author had begun to believe would never be printed, has become an American military classic. It was followed two years later, in 1892, by a sequel, The Influence of Sea Power on the French Revolution and Empire. In these two works, Mahan proved with a wealth of historical detail that a maritime nation could gain its ends without an excessive drain on its resources and even with an increase in its prosperity.
The Anglo-French Conflict
Despite the fact that the greatest war of the 19th century was fought within the borders of his own country, Mahan selected the century-and-a-half struggle for empire between England and France to illustrate his sea power thesis. His choice was made, no doubt, because the records of the Civil War available to him at the time were not sufficient for a searching analysis and he himself had been too close to appraise it objectively. Mahan saw in the Anglo-French conflict a better lesson for his own country which was then on the threshold of becoming a world power. The period he selected, from 1665 to 1815, covered the golden age of the sailing warship, and in this laboratory of the past, Mahan discovered the principle of sea power that guided the steam and steel Navy of the United States through the first half of the 20th century.
Mahan knew the Civil War as a scholar as well as a participant. His first book, entitled The Gulf and Inland Waters, was one of a three-volume series on the naval side of that conflict. He also published a biography of David G. Farragut in 1892. It was, however, in the first two chapters of his major work, The Influence of Sea Power on History, that he showed clearly the maritime nature of the Civil War.
In his two great works, Mahan defined with remarkable clarity the almost unnoticed part that the sea and its navigable waters play in the destiny of nations. His thesis, which he outlined in the initial chapters of the first of these works, was that the maritime potential of national power, or what he labeled "sea power," depended on six elements. These elements were, in Mahan's words: "I. Geographical Position. II. Physical Conformation, including, '4s connected therewith, natural productions and climate. III. Extent of Territory. IV. Number of Population. V. Character of the People. VI. Character of the Government, including therein the national institutions."
The first three of these sea power elements derive from the nature of the land in which a people live and are the physical factors in national power. The last three concern the people themselves and are the human factors in this same national power.
In the Civil War, the three physical elements and one of the human elements, number of population, were in favor of the North. Why then did the North have such a difficult time in putting down the "rebellion"? In Mahan's biography of Farragut, Admiral Farragut is reported to have said in 1864: "The enemy seem to be bending their whole soul and body to the war, and whipping us in every direction. What a disgrace that, with their slender means, they should, after three years, contend with us from one end of the country to the other."
The tenacity and ingenuity of the South in effectively carrying on the war in the face of heavy odds must have perplexed a great many of the North's military leaders during that long and bloody struggle.
An answer to the question posed by Farragut lies in the last two of Mahan's elements of sea power: Character of the People and Character of the Government. For four years, the people of the South, by their faith, their spirit, and their military ability, were able to make the human elements of national power triumph over the physical. These qualities were embodied in the person of Robert E. Lee.
Sea Power Versus the Genius of Lee
Two transcending facts of the American Civil War are the military genius of Robert E. Lee and the naval superiority of the North. Behind all the blood and sacrifice, behind the movements of armies and the pronouncements of political leaders, the war was essentially a contest between these two strategic forces. Lee's tactical opponent was the Army of the Potomac, but his strategic rival was the Union Navy.
A vast literature has been devoted to Lee's tactical genius, to his talent for winning battles, but little attention had been given to his strategic outlook, to his capacity for viewing the war as a whole. As an example, Civil War historians and buffs ponder Lee's tactical failures at Gettysburg, but miss the brilliance of a strategy that forced the larger Army of the Potomac to fight in the foothills of the Alleghenies, far from the support of a strong Navy. Had Lee succeeded in reaching the Schuylkill River and the Reading Railroad, he would have cut the entire supply of anthracite coal for the Union blockading squadrons which required three thousand tons a week.
Before discussing Lee's struggle against sea power in more detail, attention should be drawn to some perceptible facts about this almost unseen force. The first is that he who would use navigable waters for military purposes must first be able to deny these waters to the enemy. A second is that control of navigable waters gives a powerful freedom of action to its possessor, because sizable movement is the intrinsic characteristic of a ship.
The third fact about sea power is that it takes form in concentrated packages of fire power called warships. Warships of the proper type are required wherever navigable waters are to be used for military purposes. Sea power has been expressed in sailing ships of the line and aircraft carriers, river gunboats, and missile-carrying submarines. The forms of sea power change; its essence remains the same.
The fourth fact about sea power is its limitation. This Robert E. Lee never forgot. No matter how great it is, sea power must reach from navigable waters and it is effective only as far as that reach. Lee checked the sea power of the North by maneuvering his Army of Northern Virginia beyond the range of Union gunboats.
Sea power is essentially maritime strategy, and strategy is perhaps best defined as the military use of geography. To perceive the impact of geography on the Civil War, look at any map of the area that includes the 11 states of the Confederacy. The map will show a coast line as long as that of Europe from Germany around to Italy, a low, dangerous coast with many bays and inlets and behind much of it a network of inland waterways. In addition, the map will show the great Mississippi River system penetrating the Confederacy not only in a north-south but also in an east-west direction.
Struggle for control of the coast, estuaries, and rivers in the Civil War resulted in a type of naval action which, although not unique to that conflict, did dominate it to a large extent. This was the fleet-against-fort action, Union fleet against Confederate fort. In this category can be included the battles of Hatteras and Port Royal in 1861; Forts Henry and Donelson, Island Number Ten, New Orleans and Drewry's Bluff in 1862; and in the latter years, Vicksburg, the entire Charleston campaign, Mobile, and Wilmington, North Carolina. Both the action betweenMerrimack and Monitor and the war-long blockade can also be placed in the fleet-against-fort category.
In such actions, Northern officers had to fight their ships not on the high seas where they had been trained, but up rivers, between bluffs, head-on without being able to turn, through mine fields, and among innumerable shoals where grounding could mean destruction or capture. Opposing them were many of their former shipmates, denied service afloat for the Confederacy, but invaluable in the forts because of their hydrographic and ordnance knowledge.
Fleet-against-fort actions were by no means purely naval affairs. Union Army forces had to be used in assault in most of the engagements along the upper Mississippi Valley and at Fort Fisher, while at Port Royal, New Orleans, and Mobile they were needed in the follow-up. Where army forces were not employed, naval attempts alone were usually failures as was demonstrated at Drewry's Bluff in May 1862 and again in the ironclad attack on Charleston in April 1863. Rear Admiral Andrew H. Foote compared army and naval forces in such operations to blades of shears—united, invincible, separated, almost useless.
Another dominant feature of the geography of the Confederacy was the Appalachian Mountain chain which split the northern portion into two areas that were not mutually supportable. Because of its location, the only Confederate-controlled railroad which crossed these mountains was of little military use. Thus the Appalachian chain denied to the Confederacy a land strategy of interior lines.
These mountains did, however, provide the Confederacy with the strategic compensation of two strong points beyond water access. One was the Shenandoah Valley which Lee used to the greatest advantage. The second was the mountain stronghold at Chattanooga, the only gateway between the eastern and western theaters of operations. Here the military leaders of the South failed to make the best use of their favorable position.
The Maritime War in Virginia
Northern sea power reached for thousands of miles along the Atlantic and Gulf coasts and into thousands of miles more of the Mississippi River system. However, much of it had to be concentrated in the waters of the Chesapeake Bay because the rival capitals were situated on two rivers of that bay and within one hundred miles of each other. The location of Washington on the border of the Confederacy was an accident of history, but the choice of Richmond as the Southern capital is a subject for political rather than strategic study. The proximity of the capitals doubled Lee's task, for he had to protect Richmond as well as check Union sea power. He did this by an offensive-defensive strategy of maneuver to the left, away from navigable waters.
Lee kept his military thoughts to himself. They can only be conjectured, and studying a map of Virginia will help in this. Two geographic features are prominent. The first is Chesapeake Bay with its four rivers, the Potomac, Rappahannock, York, and James. These rivers lead into the heart of Virginia, one to the doors of its capital. The side that controlled these rivers had the strategic and logistic advantage of sea power.
The second prominent feature of Virginia geography is the Shenandoah Valley, an area of maneuver as favorable to the soldier as Chesapeake Bay is to the sailor. The Shenandoah Valley provided a road to Washington and the North but not to Richmond and the South. Lee used it well.
Chesapeake Bay and the Shenandoah Valley are the vital strategic areas in Virginia, and the key points within these areas during the Civil War were Hampton Roads and Harpers Ferry. Fortress Monroe, guarding Hampton Roads, never passed out of Union hands. The task of the Union Navy would have been immeasurably greater had not General Winfield Scott, in April 1861 , insisted on holding Fortress Monroe at the cost of losing Norfolk Navy Yard. This navy yard provided the Confederates with powder for Bull Run, the ironclad Merrimack and heavy ordnance for the forts on Southern bays and rivers. Had Fortress Monroe been lost, however, the Confederates would have been able to blockade Washington and perhaps besiege it instead of being compelled to cover Richmond. Throughout the war, Fortress Monroe and the Union Navy were mutual supports.
On the other hand, Harpers Ferry, strategically important, was almost tactically indefensible. It changed hands several times during the war. To have held this valuable gateway to Washington and the North would undoubtedly have been costly. A comparison between the roles played by Hampton Roads and Harpers Ferry in the Civil War demonstrates the potency and utility of sea power.
Action in Virginia
The first actions in Virginia took place at these two points in April 1861, followed three months later by the stalemate at Bull Run. In the spring of 1862 the war in Virginia really opened, on the Chesapeake Bay. General George B. McClellan, the Union Army commander, chose to advance on the Confederate capital from the east and this required a maritime campaign. As McClellan was about to start his over-water movement, Union control of Hampton Roads was threatened by the ironclad Merrimack. The Union commander was thus painfully reminded of the first fact of sea power: "He who would use navigable waters for military purposes must first be able to deny these waters to the enemy." The Union Navy, watching for a return of Merrimack after her engagement with Monitor, could not spare the ships to open supply lines on the York and James Rivers. General McClellan's huge army had to be landed under the guns of Fortress Monroe and be cooped up on a narrow, swampy peninsula, " the ragged half-island between the York and the James."
Without the support of a sufficient naval force, McClellan began a month's preparation for a siege of Yorktown. Just as the Union bombardment was to begin, the Confederate commander, General Joseph E. Johnston, abandoned the defenses and retreated up the peninsula. Johnston then used his authority as over-all commander in the area to transfer to his army some eleven thousand men defending Norfolk. Thus he forced the abandonment of that city, its navy yard, and Merrimack. When the ironclad was lost, Confederate control of the lower James River was also lost, never to be regained.
On 11 May 1862, while Merrimack was being destroyed by her own crew, a Union squadron, which eventually included three ironclads, was in the James River on its way to Richmond. To save the capital from falling, as New Orleans had fallen a few weeks before, the Confederates hastily constructed a battery on Drewry's Bluff, a natural defense point ten miles below Richmond. Obstructions were also placed in the river there. The Union squadron, stopped by the obstructions, engaged the battery for four hours on 15 May. The squadron was repulsed primarily because there was no army force with it to make a co-ordinated amphibious assault.
At this time, Robert E. Lee was military aide to President Jefferson Davis and he witnessed the fleet-against-fort action from Chaffin's Bluff across the river. A month later, after Johnston was wounded at the Battle of Seven Pines, Lee took command of the Army of Northern Virginia. He had already given some thought to forestalling the threat against Richmond by using the Shenandoah Valley. He did not believe that Johnston would stay on the Peninsula, so as early as April, he conceived a plan for employing Stonewall Jackson's troops in the Valley to threaten Washington and prevent the strong force guarding that city from reinforcing McClellan. Jackson's brilliant Valley campaign achieved this. Then, bringing Jackson to reinforce him and using the tactical principle of interior lines, Lee defeated McClellan in the series of battles known as the Seven Days, from 25 June to 1 July 1862. During the height of these battles, the Union base of supplies had to be hurriedly changed by water from the York to the James River. Lee was finally stopped at Malvern Hill with the help of gunboats. At Harrison's Landing, the site selected by their commander, Captain John Rodgers, these gunboats protected McClellan's army from further attack and kept it supplied.
With its Navy in control of the James, the Union Army could have retrieved itself by crossing the river and advancing on Petersburg to cut the rail connection to Richmond, as Rodgers had suggested. The cautious McClellan did not rise to this opportunity.
The significance of the Union naval squadron in the James River and the attack on Drewry's Bluff was not lost on Lee. While McClellan licked his wounds at Harrison's Landing, the Confederate commander had time to construct a line of defenses to protect Richmond and Petersburg from amphibious attack. Drewry's Bluff was his defense keystone.
Virginia's River Defenses
Lee was then in position to hold back the Union gunboats while he operated beyond their range, beyond the reach of sea power. The James River was fortified. The head of navigation on the York River was east of Richmond, while the head of navigation on the Rappahannock was at Fredericksburg. On the greatest of the four Virginia rivers, navigation stopped at the Great Falls of the Potomac, ten miles above Washington. Beyond this point Lee could cross the Potomac unmolested by gunboats. He could thereby use the Shenandoah Valley to invade Maryland and threaten Washington on its flank. In this way he countered the threat of sea power against Richmond.
When that city's defenses were ready, Lee struck at Second Manassas. During the next two years, every major battle in Virginia was fought west of a line from the Great Falls of the Potomac to Drewry's Bluff: Second Manassas, Antietam, Chancellorsville, Gettysburg, and the Wilderness. The strategy behind these battles reveals Lee's efforts to change the amphibious war in Virginia to one of land campaigns that would keep the Army of the Potomac on the defensive and neutralize Northern naval supremacy.
Even with this strategy, the Confederate commander could not entirely free himself from the tentacles of sea power. From water bases on the Potomac at Aquia Creek and on the Rappahannock at Fredericksburg, Union soldiers still threatened Richmond from the north. Only when Lee had the Army of the Potomac off balance after its defeats at Second Manassas and Chancellorsville did he dare attempt his invasions. His set-backs at Antietam and Gettysburg can be attributed as much to inadequate logistics as to intelligence leaks and faulty tactics. After each of these defeats, Lee was forced to return to his line along the Rapidan River to insure the safety of Richmond.
The war thus stalemated in Virginia. The Army of the Potomac had to keep itself between Lee's army and Washington, while Lee could not venture too far north of Fredericksburg or use the Shenandoah Valley offensively without exposing Richmond.
This stalemate ended in 1864. By this time, it was evident to the North that the Confederacy was in fact the Army of 'Northern Virginia and that this army had to be destroyed before the "rebellion" could be put down. Conscription, which had been in effect for two years in the South, was adopted in the North, and this turned one element of sea power, numbers of population, back in the North's favor.
Ulysses S. Grant now had command of all the Union armies. He had learned the effectiveness of water movement and amphibious operations in the West. His plan was for the Army of the Potomac to hold and crush Lee between Fredericksburg and Richmond, while the Army of the James, under Benjamin F. Butler, made an amphibious advance on the Confederate capital. Butler failed miserably, and a month's fighting in the Wilderness and the bloody repulse at Cold Harbor convinced Grant that he had underestimated Lee. Grant then changed his plan and advanced against Richmond via the James River as McClellan had done two years before. Once more the Union supply base was transferred to the James, but this time to the south side at City Point, now Hopewell.
Lee countered with his Shenandoah strategy of the left to relieve the pressure that Union sea power was again putting on his right. He sent Jubal Early with the remnants of Jackson's II Corps to sortie from the Valley. The city of Washington was threatened until Grant sent the VI Corps of the Army of the Potomac by water from the front at Petersburg. The blue-clad veterans marched fresh and ready off transports at Washington's wharves about the time that Early's tired troops reached the outskirts of that city. Lee had played his last trump in Virginia. He now had no alternative but to defend along the Richmond-Petersburg line that he had constructed two years before.
The Maritime War Outside Virginia
The maritime war elsewhere along the coast took a different form. By tremendous naval effort, an economic blockade was established and maintained, but enough material was brought through it to keep the Confederates supplied with arms and to make speculators rich. Historians have not yet determined how effective the blockade really was. The South could have been cut off from European help early in the war if the ports of Wilmington, North Carolina, Charleston, South Carolina, and Mobile, Alabama, had been captured by amphibious operations. Lee's strategic genius in keeping Union forces pinned to the defense of their capital prevented the availability of sufficient troops for this purpose. Warships had to do what troops should have done—close the ports to foreign trade. Thus, warships were not free to perform the Navy's primary function, protecting the nation's shipping and its sea lines of communication. The American merchant marine was virtually driven from the sea by a half-dozen Confederate cruisers.
The anomaly of the Civil War is that the maritime campaigns were conducted most effectively inland, on the rivers of the West. The key point on the Mississippi system, Cairo, Illinois, at the junction of the Ohio and Mississippi Rivers, was seized on 23 April 1861, by a Union force sent from Chicago. The capture of Forts Henry and Donelson in February 1862 opened the Tennessee and Cumberland Rivers as Union lines of supply, thereby giving the North control of western Tennessee and providing a water base at Nashville for operations in the eastern part of the state. Two gunboats at Shiloh helped save a Union army while others opened the Mississippi River as far as Vicksburg. A Southern land offensive into Kentucky in the fall of 1862 succeeded in dividing the Union forces and drawing them for a time from their water lines of advance. The Confederates were thereby able to hold Vicksburg and Port Hudson for another year and keep open their line of supply from Arkansas and Texas via the Red River which joins the Mississippi between these two points. It was not until July 1863 that Vicksburg and Port Hudson were taken, the Mississippi brought completely under Union control and the trans-Mississippi states cut off.
The importance of the rivers in the Civil War was not lost on the French historian, the Comte de Paris, who remains the best overall military analyst of the war. In his History of the Civil War in America, Vol. I, he states:
We shall see the rivers performing a double part in the strategic movements. Onthe one hand, they secure unlimited resources for revictualing armies, being accessible to an indefinite number of steamers, which can convey the supplies and reinforcements that are needed. On the other hand, they afford armies powerful means for assuming the offensive, by enabling ships of war to support their movements and protect their lines of communication in proportion as they are extended.
This author also pointed out that railroads could easily be cut unless large elements of advancing forces were left behind to protect them. This fact became painfully evident to Union commanders in the autumn of 1863 when the navigable waters of the Tennessee and Cumberland Rivers no longer reached to support their armies advancing against the strong mountain gateway of Chattanooga and the industrial city of Atlanta. It took a year to make the 260-mile advance overland from Nashville to secure these two important points.
The war beyond the Appalachians was virtually over in the fall of 1864. The Union armies of the West, then combined with the sea power along the Atlantic Coast to effect the great encircling movement that brought the war to a close. After General William T. Sherman captured Atlanta, he had to turn almost immediately to protect his railroad lines of communication. This dilemma forced on him the decision to split his army. He sent part of that army under General George H. Thomas back to the water base at Nashville to deal with the remaining Confederate forces in the West. Then he cut his line of communication and made the strategic movement that has come to be known as the "March to the Sea." He himself described this march as only a shift of base, made possible because the Union Navy from its base at Port Royal, South Carolina, controlled the waters of the entire South Atlantic coast. This control assured Sherman of supplies at any point on that coast.
Sherman cut the Confederacy as with an axe. He forced the abandonment of Charleston and Savannah without battles. Travelinglight and supported from the coast, he marched through the Carolinas for the closing actions of the war. After the fall of Wilmington, North Carolina, his XXIII Corps was brought by river, rail, and sea transport from the heart of Tennessee through Cincinnati and Washington to join him in North Carolina.
The vise was closing. Sea power, held in check by the genius of Robert E. Lee, was released by the strategic insight of Grant and Sherman. In the end, sea power prevailed and brought about the downfall of the Confederacy.
This did not happen, however, until a capable Northern leadership was able to integrate in its favor all six of Mahan's elements of sea power, the human as well as the physical.
Rear Admiral Hayes was assisted in the preparation of this article by Miss Lillian O'Brien of Baltimore, who also has been associated with him in transcribing and editing the Civil War Letters of Rear Admiral S. F. Du Pont.