At the Waterfront Hall on Monday, Barack Obama paid tribute to Belfast's pivotal role in the founding of the United States. The president told his audience how, 325 years ago, a ship set sail from what is now Lanyon Place, filled with men and women, bound for Chesapeake Bay on the Maryland-Virginia coast, all dreaming of a new life.
What the president may not have known is the role played by one Belfast man in keeping slave ships out of the city at a time when other British ports were embroiled in the murky transatlantic trade. That man was Thomas McCabe.
In 1786, several Belfast merchants, including Waddell Cunningham, had called a meeting at the Exchange and Assembly Rooms in Waring Street. The purpose of the meeting was to discuss setting up a slave-ship company.
Cunningham and Thomas Gregg were the main architects of the scheme. Both had returned from New York, where they had traded extensively and successfully with the Caribbean.
Their plan was to ship goods to the Gold Coast, purchase the captured African slaves, deliver them to the West Indian sugar plantations, returning to Belfast with cargoes of sugar and brandy.
They saw an opportunity to acquire vast wealth from this trade, similar to that achieved by merchants in Bristol and Liverpool.
What they hadn't taken into account was the attitude of many radical Presbyterians in Belfast. The intervention of Thomas McCabe, a goldsmith and watchmaker from North Street and a member of the First Presbyterian Church in Rosemary Street, meant that the slave-ship company never saw the light of day.
To emphasise the extent of opposition to the slave trade in Belfast, in 1791, Olaudah Equiano, the celebrated freed slave, visited Belfast to publicise his book, The Interesting Narrative Of The Life Of Olaudah Equiano, or Gustavas Vassa, the African, then in its fourth edition.
He was received enthusiastically by most of the citizens when he arrived in the town and lodged with the woollen draper and United Irishman Samuel Neilson.
During his stay in Belfast, Equiano visited the local bookshops and it is estimated that he sold around 1,900 copies of his book during his nine-month stay in Ireland.
When Equiano left Belfast, the Northern Star newspaper (founded in 1792) continued to give wide coverage to anti-slavery propaganda. Some Belfast people, including one Martha McTier, refused to use sugar, knowing where it originated.
It is ironic that, though a slave-ship company failed to emerge, Belfast merchants had extensive trade links with the Caribbean. One example was that of Captain John McCracken, father of Henry Joy McCracken, one of the founders of the Society of the United Irishmen.
Captain McCracken was involved in trade with the West Indies, as were many others, but was never involved in the transportation of slaves.
Indeed, there is a letter, dated May 26, 1760, written by Francis Joy (founder of the Belfast News Letter), in which he congratulates "son McCracken" on his safe return from the West Indies, as many ships had been taken by the French off the Irish coast.
Also during 1783, the number of shoemakers in Belfast increased as they received orders for the supply of broad-fitting shoes for the slaves on the sugar plantations. Waddell Cunningham, one of the main movers behind the failed attempt to set up a slave-ship company, was a member of the Second Presbyterian Church in Rosemary Street. S. Shannon Millin, author of two excellent books – Sidelights On Belfast History (1932) and Additional Sidelights On Belfast History (1938) – described the slavery accusation against Cunningham as "false and calumnious" and a "cock and bull story".
Millin, like Cunningham, was a member of the Second Presbyterian Church in Rosemary Street and he possibly felt obliged to defend Cunningham and the congregation against this perceived calumny.
But, after Millen had secured access to the full set of Dr William Drennan's letters at the Public Records Office, he discovered a letter from Drennan to Martha McTier confirming that Thomas McCabe had written to him telling him of the aborted plan for a Belfast slave-ship company.
Millin wrote to the News Letter on September 16, 1932, apologising for his mistake and accepting that Cunningham had been involved. (Millin should probably not have made such a fuss about the slave-ship company, as Cunningham owned a sugar plantation in Dominica.)
In researching this story, I didn't consider the white slave trade – Europeans captured as slaves. The Rev Nigel Playfair, minister of the First Presbyterian Church in Rosemary Street, found a manuscript in the British Library: it was an account of a member of his church, John Whitehead, who, in 1691, had been captured by pirates operating out of Tunisia.
Whitehead was held captive there and, when released, he wrote an account of his experiences. The manuscript found its way into the collection of Hans Sloane, the noted Co Down-born physician.
It, along with many thousands of Sloane's papers, was the basis for the early development of the British Library.
In 1807, the anti-slave campaigner William Wilberforce was successful in getting legislation passed in the House of Commons to abolish slavery.
On August 12, 1814, Wilberforce wrote to Lord Castlereagh, the foreign secretary, highlighting that British commerce had, in fact, increased since the abolition of the slave trade.
The great-great-great-great grandson of William Wilberforce, also called William, visited the First Presbyterian Church in Rosemary Street in 2007 on the 200th anniversary of the abolition of slavery.
His visit was in appreciation for the stance taken by the First Presbyterian Church – and particularly by Thomas McCabe – against the slave trade back in 1786.
Wilberforce brought with him a heavy metal casket given to William Wilberforce by the slaves in thanks for his efforts in abolishing the slave trade.
That casket was made from the shackles that the slaves had worn on the sugar plantations.
Raymond O'Regan's Hidden Belfast: Benevolence, Blackguards and Balloon Heads is published by Mercier (£17.50)