Robert Burns and the fight to end slavery
Robert Burns, the great Scottish bard, never travelled to America but his poetry and songs had a profound effect on the emerging nation.
Burns' work was wildly popular in the US from the moment it was first reproduced by "pirate" printers in Philadelphia in 1787 and it had a huge impact on the views of generations of Americans.
Among the poet's many fans were the most influential African-American of the 19th Century and the man widely regarded as America's greatest president.
Both Frederick Douglass and Abraham Lincoln regularly cited the "genius" of Burns and used his philosophy of egalitarianism and the worth of all men to fuel their political campaigns.
When Burns was born in 1759, the United States was still a British colony and throughout his teenage years the British Crown was in conflict with the upstart Americans.
His radical views were heavily influenced by what he learned of the US Revolutionary War.
Arun Sood, author of Robert Burns and the United States of America, told the BBC documentary Burns in the USA: "Burns wrote a handful of poems, songs and letters that mention America. The common theme is an association with liberty."
By the time of Burns' death in 1796, at the age of just 37, it was becoming clear that ideals in the Declaration of Independence were not coming to pass.
The enslavement of black people was endemic in the States.
In the fight to end it, Douglass and Lincoln both drew, in different ways, on the work of Burns.
Frederick Douglass started out as a slave in Maryland but escaped to the northern States in 1838, at the age of 20, and started to make strong arguments as an abolitionist.
His final home is now a museum containing his most precious possessions, including a treasured copy of the Complete Works of Robert Burns.
Mr Sood says Douglass enlisted Burns into his own discourse on slavery and abolition.
Douglass described how Burns himself had lived in the midst of a "bigoted and besotted clergy" and how the Ayrshire ploughmen had been looked upon as being "little better than a brute".
Douglass wrote: "He became disgusted with the pious frauds, indignant at the bigotry, filled with contempt for the hollow pretensions set up by the shallow-brained aristocracy. He broke loose from the moorings which society had thrown around him."
For Douglass, Burns was a man full of faults but "far more faultless than many who have come down to us in the pages of history as saints".
Burns' focus on egalitarianism and liberalism were attractive to Douglass, despite the flaws in the poet's nature.
As his fame grew Douglass became afraid that he might be captured and returned to slavery.
In 1845 he embarked on a tour to Britain to gather support for abolitionism.
The former slave presented himself as a cultured and educated man even though he had little formal schooling.
Prof Gerard Carruthers, of the Centre for Burns Studies at Glasgow University, says: "One of the things that gives him the confidence to appear educated is the exemplar of Robert Burns who had a similar kind of formative experience - non-university, self-taught, but as cultured as anyone else."
In Scotland, Douglass lectured on black emancipation and lobbied the Free Church over taking money from slave-owning states.
He also took a detour to see the birthplace of his poetic mentor and meet Burns' elderly sister Isabella and two of his nieces.
Douglass wrote about his trip to the home of the "brilliant genius" Robert Burns in the New York Weekly Tribune.
He wrote: "I have felt more interest in visiting this place than any other in Scotland for as you are aware, painfully perhaps, I am an enthusiastic admirer of Robert Burns."
The trip to Britain was a great success. He had raised the profile of his cause and his supporters had raised enough to purchase him from his slave owner in the States.
In 1847, Douglass returned to the US a commanding and influential speaker and free man.
It was Douglass who, during the civil war, forced home the argument to Abraham Lincoln that slavery should be abolished immediately.
The president made the emancipation proclamation in 1863, making the freeing of slaves an explicit goal of the war.
Arun Sood says: "Douglass was a hugely gifted orator and a very charismatic individual. During the civil war era, Douglass frequently alluded to Burns's songs and poems, particularly when trying to encourage men of colour to enlist in the Union army.
"He would tout the line that A Man's A Man For A' That, regardless of colour."
"Lincoln believed very much in the founding documents of the United States that talk about all men being created equal and that's something you see in the poetry of Robert Burns as well," says Erin Carlson Mast, director of President Lincoln's Cottage.
"This idea of natural rights is something that Lincoln really latched on to."
Lincoln had little formal education but he was a voracious reader. When he arrived in New Salem, Illinois, at the age of 21 he had a neighbour who had 27 books.
Prof Carruthers says: "With a name like Jack Kelso or Jock Kelso, it is little surprise that this is a Scotsman. He is certainly one of Lincoln's mentors."
Sam Wheeler, state historian of Illinois, says: "Lincoln heard Kelso recite the words of Robert Burns complete in the Scottish dialect, acting out the poems and Lincoln picks up that habit."
According to Prof Carruthers: "What I think is going on is that Lincoln, like many New World cultural figures, is looking for something that isn't British, isn't English.
"Burns to some extent plays into that alternative culture that America is looking for."
The final record of Lincoln's affections for Burns comes from his secretary John Hay. He describes the president's mood as they travelled down the Potomac river.
Erin Carlson Mast says: "John Hay reflects that in the April of 1865 the war has come to an end, that Lincoln himself recites extensively from Robert Burns without notes, all from memory."
One of the poems that came into Lincoln's mind that day is one of Burns saddest, Lament for James, Earl of Glencairn.
Less than a week later Lincoln was shot dead at a theatre in Washington.
However, the fight to end slavery throughout the Union had been won and the nation's founding argument of liberty for all had been upheld.