A Savage War: A Military History of the Civil War

“First Battle of Charleston Harbor,” hand-colored lithograph by Currier & Ives. Wikimedia Commons/Public domain

An excerpt from Williamson Murray and Wayne Wei-siang Hsieh's new book.

Editor’s Note: The following is excerpted from A Savage War: A Military History of the Civil War by Williamson Murray & Wayne Wei-siang Hsieh © 2016 by Princeton University Press. Reprinted by permission.

It would take until the winter of 1863/64 for Grant to formulate a victorious Federal military strategy of overwhelming and coordinated military pressure across the whole breadth of the Confederacy’s land and sea frontiers, and a full year’s worth of campaigning between 1864 and 1865 to execute that strategy. Nevertheless, one should not believe that the Federal cause saw a complete absence of strategic planning at the outset of the war. In what the Northern press later dubbed the Anaconda Plan, Scott had proposed a Union military strategy early in the war combining a naval blockade with a waterborne expedition down the Mississippi “to clear out and keep open this great line of communication in connection with the strict blockade of the seaboard, so as to envelop the insurgent States and bring them to terms with less bloodshed than by any other plan.” Union naval power would also seize New Orleans at the Mississippi’s mouth, while riverine transport would allow the proposed expeditionary force to turn Confederate positions. Scott estimated in May 1861 that the Mississippi expedition would require approximately 60,000 soldiers, supported by forty steam transports and twelve to twenty gunboats.

Later that month, in a missive to his future replacement, McClellan, Scott adjusted his estimate and called for a slightly larger force—roughly 80,000 men, divided into two columns, one spearheaded and supported by gunboats, while the second column marched in parallel via land. Scott asked McClellan for his military opinion on how many troops would be necessary for this campaign, and for advice on the composition of the proposed river fleet, but McClellan never properly replied. Perhaps the senior general, however, had reminded the self- styled “Young Napoleon” of how he had utilized sea power to great advantage during the Vera Cruz campaign, in which McClellan had served as a lieutenant.

Whatever the source of the idea, the younger general early on recognized the potential advantages of Union sea power. He called for a naval force to help protect Cairo as early as April, and he also supported Commander John Rodgers’s early efforts to build a fleet of river gunboats. Shortly after he moved east to take command of the Army of the Potomac, McClellan also proposed in his first written campaign plan of 2 August that “an essential feature of the plan of operations will be the employment of a strong naval force, to protect the movement of a fleet of transports, intended to convoy a considerable body of troops from point to point of the enemy’s seacoast; thus either creating diversions and rendering it necessary for them to detach largely from their main body in order to protect such of their cities as may be threatened; or else landing and forming establishments on their coast at any favorable places that opportunity might offer. This naval force should also cooperate with the main army in its efforts to seize the important seaboard towns of the rebels.”

In his use of sea power, McClellan revealed a skepticism of the value of committing all military efforts to a decisive and climactic battle and a recognition of the importance of mobility and logistics. He recognized that Union naval superiority, if coastal defenses could be overcome, gave its armies secure lines of communications to the Confederacy’s littoral regions, including many of its most important cities. Even more importantly, mastery of the sea could provide Federal forces both operational flexibility and the potential for surprising Confederate defenders, which could help compensate for the Confederacy’s interior lines of communication (that is, the Confederacy’s ability to use its internal rail network to reinforce threatened points more quickly than could the Union mass its forces in response). During both their prior wars with the United States, the British had ably exploited such advantages. In the Revolution, the Royal Navy had doomed George Washington’s defense of New York City in 1776, and in the War of 1812, its domination of the Chesapeake had played a crucial role in Washington’s fall. The US Army Corps of Engineers (of which McClellan had been a proud member as a lieutenant) had constructed a system of seacoast fortifications designed in large part to defend the republic from British joint operations in the event of a third war with England. While the British example indicated that sea power could not by itself win a war, the Union’s final set of victorious campaigns in 1864–65 included operations to capture the important port cities of Mobile and Wilmington, and Grant’s original campaign plan included an important subordinate expedition to attack Richmond from the southeast via a seaborne expeditionary force, led by Butler.