IN a little-known square behind Manchester Town Hall stands a statue of US president Abraham Lincoln.

Although it is hidden away, it represents a huge event in the radical history of Manchester — when thousands of workers supported an embargo of cotton during the US civil war, helping end slavery in the US but at a cost of idle mills and hunger to workers in Lancashire’s cotton industry.

Sunday is the anniversary of the date in 1863 when Lincoln wrote a letter to “the working men of Manchester” in acknowledgement of their support for the embargo of cotton from the southern Confederate states as the US civil war raged.

In the mid-1800s Lancashire, and in particular Manchester, was the world centre for the cotton textile industry.

“Slave cotton” was a potential source of huge funding for the Confederate cause in the war which was to drag on from 1861 to 1865.

From April 1861, the Northern states’ navy had blockaded the Confederacy’s southern ports, preventing most cotton exports.

In Britain, while the government expressed muffled support for the Unionist cause in the civil war, cotton mill owners and shipping lines were pressing Westminster to order the Royal Navy to break the blockade to restore their flow of profits.

There was a clear divide between the employer class who wanted slave cotton and the workers who supported the blockade despite the hardship it forced upon them.

In London Confederate flags flew in the Mall. They flew from employers’ buildings in Liverpool and in Manchester.

The port of Liverpool and the mills of Lancashire were the destinations for 75 per cent of the cotton produced in the Confederate slave plantations.

In December 1862, a mass meeting called in Manchester by trade unions and trades councils was attended by 6,000 workers who voiced support for the embargo — and decided to refuse to handle cotton picked by slaves.

The embargo was costing them dear. An estimated 60 per cent of Lancashire’s cotton mills were reported to be idle. Belfast — known as “linenopolis” for its domination of the linen industry — suffered similarly.

Alan Percy of Manchester Radical Traditions said: “Most people don’t know why there’s a statue of Abraham Lincoln in the centre of Manchester. It’s about Manchester’s industrial past and the battle to end slavery in the US.

“In 1862 Manchester was in the grip of a so-called cotton ‘famine’ as a result of the Northern blockade of the US’s southern ports which reduced the flow of cotton to Great Britain and the rest of the world. It caused an economic depression in Lancashire especially but also in the whole of Britain.

“Much of the British elite was advocating to break the blockade and restart the use of Confederate cotton.

“As a result, workers and their unions organised a meeting at Manchester Free Trade Hall explicitly to support the struggle against the Confederates despite the great hardship, on moral grounds. Six thousand attended the mass meeting.

“The organisers of that meeting sent a letter to Abraham Lincoln declaring support for the blockade, saying they were going through great hardship but that the fight against slavery was more important — important for all working people.”

A letter to Lincoln from the mass meeting organisers was sent on December 31 1862. It expressed support for the independence of the US.

But it also said: “One thing alone has, in the past, lessened our sympathy with your country and our confidence in it — we mean the ascendency of politicians who not merely maintained negro slavery but desired to extend and root it more firmly.

“Since we have discerned, however, that the victory of the free North, in the war which has so sorely distressed us as well as afflicted you, will strike off the fetters of the slave, you have attracted our warm and earnest sympathy.”

On January 19 1863, Lincoln wrote from the Executive Mansion, Washington: “To the Working-men of Manchester: I know and deeply deplore the sufferings which the working-men of Manchester, and in all Europe, are called to endure in this crisis.

“It has been often and studiously represented that the attempt to overthrow this government, which was built upon the foundation of human rights, and to substitute for it one which should rest exclusively on the basis of human slavery, was likely to obtain the favour of Europe.

“Through the action of our disloyal citizens, the working-men of Europe have been subjected to severe trials, for the purpose of forcing their sanction to that attempt.

“Under the circumstances, I cannot but regard your decisive utterances upon the question as an instance of sublime Christian heroism which has not been surpassed in any age or in any country.

“It is indeed an energetic and re-inspiring assurance of the inherent power of truth, and of the ultimate and universal triumph of justice, humanity, and freedom.”

The statue of Lincoln was created after the first world war and sent to London by a US Republican admirer of Lincoln.

Strangely the authorities in London could find no place for it and it ended up in Manchester.

Sunday’s commemorative event takes place at the statue in Lincoln Square, next to Albert Square, behind Manchester Town Hall, at 2pm.