The Anaconda Plan: The Real Union Naval Blockade Strategy

Military History: The US Civil War

Chapter 4 · The Anaconda Plan: The Real Union Naval Blockade Strategy

Bull Run (Chapter 3) was loud, visible, and quickly lost. The Union's slower strategy was much less dramatic: close the South's ports, take control of the Mississippi River, and let economic pressure do its work. It was mocked when it was first proposed. It turned out to be one of the most important reasons the North won.

Winfield Scott's Plan

In 1861 the Union's senior general was Winfield Scott, then in his seventies and a veteran of the War of 1812 and the Mexican War. In letters in May 1861 he set out a strategy with two parts.

1 · Blockade

Close every Confederate port so the South couldn't sell its cotton abroad or import weapons, machinery, and supplies.

2 · The Mississippi

Send an army and gunboats down the Mississippi River to split the Confederacy in two, cutting off Texas, Arkansas, and Louisiana from the east.

3 · Wait

Scott hoped that squeezing the South this way might bring it back into the Union with far less bloodshed than invading it directly.

Mocked, Then Used The press ridiculed the plan as too slow and passive, comparing it to an anaconda slowly squeezing its prey — which is where the name comes from. The public wanted a quick march on Richmond. Scott retired in late 1861 and the plan was never formally adopted as a single strategy. But its two main parts, the blockade and the Mississippi, became central to how the Union actually won.

The Blockade: An Enormous Task

Lincoln proclaimed a blockade of Southern ports on 19 April 1861, a week after Fort Sumter.

The challenge	The scale
Coastline to watch	About 3,500 miles of Atlantic and Gulf coast, including 12 major ports
Union ships suitable for blockade duty in 1861	Only a handful
Union Navy by 1865	About 670 ships

A Legal Complication Under international law, a country blockades an enemy, not its own rebellious citizens. By declaring a blockade, the Union was in effect treating the Confederacy as a belligerent in a war — even though Lincoln insisted it wasn't a real country. Britain and France used this to recognise the Confederacy as a belligerent (though never as an independent nation), which let it buy ships and supplies from neutrals.

Taking Bases on the Enemy Coast

Steam warships needed coal, so the Navy needed harbours close to the blockade. Early joint Army-Navy operations captured the forts at Hatteras Inlet, North Carolina (August 1861) and Port Royal, South Carolina (November 1861), giving the fleet bases along the Southern coast itself.

Blockade Runners

The Confederacy fought back with blockade runners: fast, low, often grey-painted steamships, many built in Britain, that ran between Southern ports and neutral harbours such as Nassau in the Bahamas, Bermuda, and Havana. They carried cotton out and brought back rifles, gunpowder, medicine — and, very profitably, luxury goods.

Period	Roughly how often a runner was caught
1861–1862	About 1 in 10
1863–1864	About 1 in 3
End of the war	About 1 in 2

"Leaky" Doesn't Mean Useless Many runners got through, and some historians have argued the blockade didn't matter much. But the blockade didn't have to stop every ship. By making each voyage risky, it pushed shipping costs up, forced runners to carry small, high-value cargoes rather than bulk goods like railroad iron, and slashed Southern trade overall. Cotton exports fell by about 95% compared with before the war.

King Cotton Backfires Confederate leaders believed Britain's textile mills depended so heavily on Southern cotton that Britain would have to intervene. In 1861 they even held back cotton themselves to increase the pressure. It didn't work: British warehouses had a large surplus from the huge 1860 crop, new supplies came from Egypt and India, and Britain had no wish to fight a war on behalf of a slaveholding republic — especially after the Emancipation Proclamation in 1863.

The Ironclads: Hampton Roads, March 1862

The Confederacy couldn't build a navy to match the Union's, so it tried new technology instead. At Norfolk, Virginia, it rebuilt the burned Union frigate Merrimack as an armoured ironclad, the CSS Virginia, to break the blockade.

8 March 1862 The Virginia attacks the wooden Union blockading ships at Hampton Roads. It rams and sinks the USS Cumberland and destroys the USS Congress; around 250 Union sailors are killed. Union cannonballs bounce off its armour.
Night of 8 March The Union's own new ironclad, the USS Monitor — a low, flat ship with a revolving gun turret — arrives just in time.
9 March 1862 The two ironclads fight for about three hours at close range. Neither can seriously damage the other. The Virginia withdraws; the blockade holds.

A Draw That Changed Every Navy Tactically the battle was a draw, but strategically it was a Union success: the blockade survived. And it showed every navy in the world that wooden warships were obsolete. Britain and France stopped building wooden-hulled ships of the line, and "monitor" became the name for a whole type of turreted warship.

The River War

The second half of Scott's idea — controlling the Mississippi — was fought with river gunboats and armies working together.

February 1862 Union forces under Ulysses S. Grant, with river gunboats, capture Forts Henry and Donelson in Tennessee, opening the Tennessee and Cumberland Rivers into the Confederate heartland.
April 1862 Flag Officer David Farragut's fleet runs past the forts guarding the lower Mississippi and captures New Orleans, the Confederacy's largest city and port.
1862–1863 Union gunboats and armies push down from the north and up from the south, leaving one key Confederate stronghold still controlling the river — Vicksburg (Chapter 7).

The Blockade Closes

Mobile Bay, August 1864

Farragut forced his way into Mobile Bay past Confederate mines (then called "torpedoes"). His famous order is usually quoted as "Damn the torpedoes, full speed ahead!" — though the exact wording was only recorded later.

The First Submarine Kill, February 1864

The Confederate submarine H.L. Hunley sank the USS Housatonic off Charleston — the first time a submarine sank a warship. The Hunley itself was lost with its crew.

Fort Fisher, January 1865

The fall of Fort Fisher closed Wilmington, North Carolina, the last major Confederate Atlantic port. Lee's army lost its last real link to overseas supplies.

Questions to Sit With

Why do you think a slow, economic strategy was so unpopular in 1861, even though it turned out to be effective?

If many blockade runners got through, how would you measure whether the blockade "worked"?

Hampton Roads was a tactical draw. Why can a draw still be a real strategic victory for one side?

Quick Reference — Chapter 4

General Winfield Scott's May 1861 plan: blockade the South's ports and take the Mississippi; mocked as the "Anaconda Plan," never formally adopted, but central to Union victory
Lincoln proclaimed the blockade on 19 April 1861; it covered about 3,500 miles of coast and 12 major ports; the Union Navy grew to about 670 ships
Blockade runners sailed via Nassau, Bermuda, and Havana; the capture rate rose from about 1 in 10 early on to about 1 in 2 by 1865; cotton exports fell about 95%
"King Cotton" diplomacy failed: Britain had surplus cotton, new sources, and no wish to back a slaveholding state
Hampton Roads (8–9 March 1862): CSS Virginia vs. USS Monitor — a draw that kept the blockade intact and made wooden warships obsolete
River war: Forts Henry and Donelson (February 1862), New Orleans (April 1862), leading toward Vicksburg
Mobile Bay (August 1864), the Hunley (February 1864), and Fort Fisher (January 1865) closed the blockade

What's Next

Chapter 5: Antietam (1862): The Real Bloodiest Single Day in American History.