Anaconda was the strategic plan proposed by General Winfield Scott early in the US Civil War. Scott’s concept was to defeat the Confederate States of America (CSA) through economic measures rather than a land war. Its purpose was to devise an approach to prevent imports and exports, which would squeeze and strangle (like the snake) the Confederacy into submission. Scott thought that by depriving the South of foreign trade and the ability to import or manufacture weapons and military supplies, the war could be won with a minimum of battlefield casualties.

Lloyd W Klein explains.

First, if you missed it, read Lloyd’s piece on how the Confederacy funded its war effort here.

A cartoon-esque map of General Winfield Scott's Anaconda Plan to defeat the Confederacy in the American Civil War.

Scott reasoned that the vulnerability of a southern nation was its absence of manufacturing, supplies, and weapons production in the region. He recognized that the seceded states depended on bringing military and consumer imports in, and trading cotton and agricultural exports out. Since the CSA trading partners were overseas and there were no land connections, its economy depended on open rivers and seas. Scott devised a plan for a naval blockade of the ports of the Confederate Atlantic shoreline, an invasion and occupation down the Mississippi River, and the consequent strangulation of the South by combined Union land and naval forces. Scott expected that a land war would be a long, arduous undertaking despite the general opinion that it would be over in weeks.

The two objectives of the blockade were: 1) to prevent war material, manufactured goods, and luxury items from reaching the South to boost their war effort and morale at home and 2) to stop the exportation of raw cotton to foreign manufacturers, which would bring cash to the Confederate economy. By blockading the southern ocean ports and the Mississippi River, its military would slowly suffocate as supplies dwindled and the country became isolated from its trading partners.

Southern Economic Realities

The ante bellum economy of the South relied on bringing manufactured goods from the Northern states and trading raw agricultural products with foreign countries. The South grew crops and raw materials, which were then sold to industrial centers and in return, manufactured goods were purchased. In addition, the South needed markets to sell its cotton and other cash crops. Before the war, the South relied on coastline ports to ship goods and products to other regions and countries.

More specifically, southern economy was dependent on exporting cotton to Great Britain and to the Northeastern states, where clothes and other items were manufactured. The revenue from cotton sales were used to purchase finished products and goods. Food was purchased from Texas and Arkansas or the Midwestern states. Southern reliance on cotton sales and the absence of manufacturing centers in the region delineated why the prewar Southern economy was dependent on maritime trade.

The only way to transport these goods to the consumer were by rail. The blockade overburdened roads and the railroad system in the South, which were not designed to transport troops north-south where the troops needed to go but rather west-east towards the ocean. This increased the cost of transporting goods, raising the prices on agricultural products and stressed the Southern economy. The main role of the railroads before the war was to bring goods to port; the opposite direction was rarely used for transporting heavy loads from the ports to the cities or countryside. This pattern would have to be modified rapidly to stay in the war.

Moreover, the South in 1861 has limited facilities to produce the weapons of war. Only one iron works existed that could produce artillery weapons and armaments, and few manufacturing centers of guns and bullets. All of these would have to be imported to engage in war once those stolen from federal armories in the South had been used.

Proclamation and Management of the Blockade

US Secretary of State William Henry Seward recommended adopting the blockade immediately following the firing on Fort Sumter. Union military commanders were not sanguine about the idea, preferring a rapid attack strategy to a slow suffocation, believing that the war would be rapidly over.

On April 19, 1861 President Abraham Lincoln issued the Proclamation of Blockade Against Southern Ports, putting the Anaconda Plan into effect. The blockade was extended to include North Carolina and Virginia on April 27. The Union Navy had established blockades of all major southern ports, notably New Orleans and Mobile, by July 1861. Other important ports included Norfolk, Charleston, Wilmington and Savannah.

To manage the blockade, a commission called The Blockade Strategy Board was created by the United States Navy at the direction of Assistant Secretary of the Navy Gustavus Fox. The group was comprised of: Samuel Francis Du Pont, who acted as chairman; Charles Henry Davis; John Gross Barnard; and Alexander Dallas Bache. They first met in June 1861 to determine how best to stop maritime transport to and from New Orleans and Mobile. Their analysis of the Atlantic ports was very good from the start but that of the Gulf Coast was not. At that time, detailed oceanographic knowledge was not available for the Gulf.

Legal Implications and Foreign Response

Lincoln was immediately confronted with the question of whether the secession of the South should be regarded as rebellion or as war. The fact that the CSA had a government elected by representatives of the people made declaring it a rebellion appear politically motivated. The US continued to insist that the parties to the contest were not belligerents, and that rebellion was not a war. From the legal point of view, the action had to be regarded as armed insurrection. Secretary of the Navy Gideon Welles advised an undeclared blockade; his idea was to prevent foreign governments from granting the Confederacy belligerent status or recognition as an established nation.

Others suggested that the southern ports be declared closed, which was a legal act. Legally, governments have the right to close its own ports, and to impose penalties upon ships attempting to enter. Only an executive order would be necessary, and would not raise these thorny issues. However, such an order could only be enforced in US waters, which would not allow for stopping ships on the high seas. Additionally, violations would only be breaking a US revenue law, which were only to be adjudicated in a federal court in that state. And, European nations would not have to follow this order because it wasn’t an international law. Convincing foreign governments to view the blockade as legitimate was crucial. The search and seizure of foreign vessels on the high seas, even though bound for the embargoed port, is an act of war, unless there is a declared and established blockade. But, once that happens, the nations are legally belligerents.

As Welles anticipated, Great Britain granted belligerent status on May 13, 1861, Spain on June 17, and Brazil on August 1. Other foreign governments issued statements of neutrality. These governments acknowledged the right of the US to stop and search neutral ships in international waters, but were concerned that the methods being used went beyond what international law allowed. Lincoln specifically noted in his announcements that the US would “follow the law of nations; this meant that the blockading ships would first issue a warning and would only capture the suspected ship on its next attempt to evade the blockade. Union ships decided arbitrarily which ships in Caribbean ports were preparing to run the blockade, waiting outside the territorial limits for those ships to clear port and then board and search.

After the war, Raphael Semmes insisted that the blockade carried recognition of the CSA since countries do not blockade their own ports. Semmes was captain of the blockade runner CSS Alabama, the most successful commerce raider in maritime history, taking 65 prizes. Late in the war, he was promoted to rear admiral and also acted briefly as a brigadier general in the Confederate States Army.

US Naval Maritime Strategy

The basic blockade strategy was simple. The Navy used lightly armed former merchant vessels close to shore, faster and more heavily armed steam frigates patrolling offshore, and cruisers that searched around the globe to interdict Confederate blockade runners and commerce raiders on the high seas.

Actually putting into practice a blockade of the southern half of the United States and a huge transcontinental river, however, was not an easy task. The Atlantic ports had numerous defenses and entrances, and the Mississippi River defended in a number of locations. To succeed, the blockading navy had to patrol 12 major ports, 189 harbors and 3,500 miles of coastline.

In fact, the US Navy was unprepared for this mission at the beginning of the war. The Union had only thirty-five modern vessels, just three of which were steam powered. Accomplishing this task required a huge building program to build ships to cover Southern seaports. Eventually, the Union produced 500 ships for the sole purpose of creating an effective blockade.

The Mississippi River comprised an entirely different problem. The Navy developed a combined-arms strategy with the Army in amphibious and coastal/riverine operations. Both forces were necessary to control of riverways and ports. River warships had to have sufficient power to run battery fire from the shore and enemy ships in an enclosed space. The river experience to that time had been all about commerce and there was no experience building boats to maneuver and carry heavy artillery in a river. These ships had to be designed and built.

Blockade Runners

Maintaining international commerce by overcoming the blockade was crucial to the CSA. Because it lacked sufficient manufacturing centers in the South, the only way to supply its military needs and keep its economy going was by international commerce. Therefore, among all of its other priorities, the CSA had to build a navy with the purpose of evading the US ships blockading its ports. Freighters were much too slow and lacked the ability to outrun or outmaneuver the Union gunboats.

By the end of 1862, the efficiency of the blockade required that only specially designed vessels could attempt to run it. The nature of their operations was risky because they are the targets that blockading fleets try to corner or fire upon. However, the potential profits and benefit were tremendous. Nonetheless, over 80% of attempts to evade the Union blockade were successful.

A blockade runner was a ship built expressly for the purpose of evading a blockade of a port or strait. Steam engines made these ships fast and difficult to trap. These ships were designed to be fast with a light draft, with exceptional maneuverability.. They were lightly armed and armored to save weight and space; their purpose was to “outrun the blockade” not fight the defending naval vessels. To remain undetected, usually the ships made their runs at night. Once sighted, the runners tried to outmaneuver or outrun the Union ships.

However, these necessary characteristics were the opposite of their purpose of carrying heavy weaponry and large amounts of supplies. Consequently, it became necessary to make multiple trips, further increasing the risk. For this reason, most were ultimately captured or sunk. In all, 1,504 blockade runners were captured or destroyed during the war. By the end of the war the Union Navy had captured 1,149 blockade runners, and had destroyed or run aground another 355 vessels.

Blockade runners were privately owned. They typically operated with a letter of marque issued by the Confederacy. These vessels carried cargoes to and from neutral ports. The four principal intermediary points were: Bermuda, Nassau, Havana, and Matamoras. There, neutral merchant ships, usually based in England or other points abroad, would exchange their cargoes. Inbound, the ships brought military supplies and other goods to the Confederacy while outbound ships exported cotton, tobacco and other goods for trade and for sale.

Great Britain played a major role in blockade running. Liverpool was especially prominent; its shipbuilding businesses were ideal for designing and building commerce raiders and blockade runners. The British developed steamships that were longer, narrower and faster than the conventional steamers guarding the American coastline, enabling them to outmaneuver and outrun blockaders. Many British businesses had investments in the South, and were suffering due to the Lancashire Cotton Famine. Furthermore, Great Britain controlled many of the ports in the Caribbean, making it an ideal partner in defeating the blockade.

Blockade runners faced an increasing risk of capture as the war continued. In 1861 and 1862, only about 10% of attempts ended in capture; but by 1863 and 1864, one in three. By war's end, imports had been choked to a trickle as the number of captures came to 50% of the sorties. Some 1,100 blockade runners were captured (and another 300 destroyed). British investors frequently reinvested their profits in the trade; when the war ended they were stuck with useless ships and rapidly depreciating cotton. Ultimately about half the investors made profits while half sustained losses. Although a large proportion of blockade runners did evade the Union defense, the strength of the blockade is better measured as the kinds of ships, and their numbers, that never tried knowing they would be caught.

Confederate Threats to the Blockade

Recognizing that the US Navy were building powerful gunboats, the Confederacy initially countered with small, fast and sleek boats called torpedo boats. These were equipped with spar torpedoes, which were easily countered by hanging chains over the sides of the boats. Another problem was that they really couldn’t carry many supplies.

The Confederates initially operated privateers, allowing them to attack Union ships. However, these ships could only sail from Confederate ports under international law; this rendered them ineffective after 1862 as the blockade ramped up. Confederate commerce raiders were very effective countermeasures. These were gunboats built with the specific purpose of attacking the blockading ships. The CSS Alabama and the CSS Florida were highly effective and rendered maintenance of the dangerous. Despite the attacks by Confederate warships, there were few Union losses. After the Alabama attacked and sank the USS Hatteras off Galveston, it was clear that small gunboats could not blockade shallow inlets without support. Consequently, strategy changed so that large flotillas were deployed, by which large numbers of naval vessels were sent to chase these Confederate warships in open seas.

Confederate ironclads were another innovation designed to break the blockade. In March 1862, the blockade of the James River was threatened by the first ironclad, CSS Virginia, often incorrectly named the Merrimac which was its original name before it was salvaged. in the Battle of Hampton Roads, the Union ironclad Monitor battled the Virginia for hours, ending the threat. Two months later, Virginia and other ships were scuttled in response to the Union Army and Navy advances.

Effectiveness of the Blockade

At first, the blockade was ineffective: in the first six weeks after Ft Sumter, the Confederacy exported 30,000 bales of cotton from Charleston in 150 ships. In April 1861, a small Union flotilla seized 16 Confederate ships and privateers in the vicinity of Fort Monroe off the Virginia coastline over two weeks. In May, two blockading squadrons were created by Welles, an Atlantic and a Gulf squadron. In October, the Atlantic Squadron was divided in to a North and South Atlantic division, and in February 1862 the Gulf squadron was partitioned into East and West Gulf division.

As the Union fleet grew in size and sophistication, more ports came under Federal control. The port of Savannah was effectively sealed by the surrender and occupation of Fort Pulaski in April 1862. Only Wilmington, North Carolina; Charleston, South Carolina; and Mobile, Alabama remained open after this point in the war.

The largest Confederate port, New Orleans, fell early in the war. There were 5 entrances to the Mississippi River, making it a very difficult military target. In April 1862, Forts Jackson and St. Philip were bombarded by Porter's mortar schooners. Farragut's fleet successfully ran past the forts on the morning of April 24, forcing the surrender of New Orleans.

Charleston was the major Confederate port on the Atlantic Coast until 1863. The city has a wide and deep harbor, with a sand bar about five miles from the harbor entrance. There were four large channels into the harbor. The port of Charleston with its excellent rail connections became the prime port due to its location just 780 miles from Bermuda and 500 miles from Nassau. Charleston was severely restricted by Admiral Dahlgren's South Atlantic Blockading Squadron in 1863 as Union ironclads moved into the main shipping channel. Although it remained open until February 1865, it never played a major role after that time.

The harbor at Wilmington North Carolina was small and had none of the natural advantages that Charleston or New Orleans possessed. For this reason, the Union did not include it in the blockade it right away. But the city had good railroads to Richmond, and because of its location it was immune to a direct assault. Its convenience to the Caribbean also made it an attractive alternative. Once this harbor became a prime destination, it required Union warships to patrol as much as 130 miles offshore to stop the trade.

Although the Atlantic coast was initially the main object of the blockade, eventually the Gulf became a very important and extremely large zone to cover. The 2000 mile coast ultimately was never fully blockaded. Only Mobile and Galveston could harbor large seagoing vessels due to the shallow waters and multiple barrier islands. Havana was the main connection to Europe from the Gulf.

Mobile was the major port in the Gulf and remained highly active until it was captured in August 1864 by Admiral David Farragut. The Battle of Mobile Bay between his fleet and the Confederate warships in the harbor closed the last major Confederate port in the Gulf of Mexico.

In December 1864, Union Secretary of the Navy Gideon Welles sent a force against Fort Fisher, which protected access to the Atlantic from Wilmington, North Carolina, the last open Confederate port on the Atlantic Coast. The fort was captured in January 1865, assuring the closure of the final Confederate port.

Impact of the Blockade on the Confederacy

The Union blockade was a powerful weapon that eventually destroyed the Southern economy, at the cost of very few lives, just as General Scott envisioned. War is largely about supporting armies with supplies throughout the various fields of conflict. The river campaigns of 1862-3 in the west crushed the South while the Atlantic blockade raised the costs. The best measure of the blockade's success was that many ships, and none of the very large ones, ever tried. Standard seagoing freighters had little chance of evading the blockade and few attempted. Restricting coastal trade put even more pressure on an outdated railroad system. Lee's army, at the end of the supply line, had to contend with a chronic shortage of supplies in the final two years.

The blockade became more effective as the war proceeded and more southern territory came under Union control. In part, the reason was that there were fewer ports to protect; but also the blockade fleets caught on to the tricks of the blockade runners. Overall, only about 10% of ships trying to evade the blockade were intercepted. However, as the Union Navy increased in size and sophistication as the war progressed, drastic reductions of shipments into Confederate ports were realized. By 1864, only one-third of attempts to run the blockade were intercepted. In the final two years of the war, only blockade runners specifically designed for this task had a reasonable chance of success.

Another significant achievement of the blockade was restricting the exportation of cotton. Before the war, the South supplied 75 to 80 percent of the world's raw cotton. Inability to export their cash crop markedly reduced cotton revenue, disrupting the Southern economy.

Unsurprisingly, southern merchants and black markets preferred the importation of luxury consumer goods, which could be sold to the wealthy, rather than weapons and medical supplies. The Confederate government eventually regulated the traffic, so that at least half were armaments and munitions.

Moreover, the southern economy had to react to these stresses, and did so in predictable yet devastating ways. Since the Southern food supply was located in the west and revenue generation east of the Mississippi, the weak and overburdened rail system became the limiting factor of supply. This forced the new Confederate national government, which had little revenue generating power, to spend its money on infrastructure rather than military or social needs.

Overall, the Union blockade did not come close to stopping all supplies from reaching the Confederacy, but it disrupted the usual flow of supplies into and out of the South enough to severely restrict its ability to make war. However, the reduced flow of goods and food led to severe shortages and higher prices. Along with Confederate currency inflation, civilian discontent became a significant war problem. The blockade demonstrated that war was no longer a matter only for soldiers, and that the effects of the war were no longer confined to the battlefield. Civilians had become combatants in the sense that undermining their morale became a military goal. Thus warfare was aimed not only at destroying armies, but also disrupting the economy and depriving people of consumer goods and food.

What do you think of the Anaconda Plan? Let us know below.

Now, if you missed it, read Lloyd’s piece on how the Confederacy funded its war effort here.