What possessed Scotland's Chief Medical Officer Sir Leslie Mackenzie and his wife Helen to risk life and limb on June 26 1928 by travelling over the mountains to Kentucky to open a tiny hospital?
But the nurses and midwives of the Highlands and Islands left a much longer lasting legacy, inspiring colleagues around the world.
Their exemplary care of mothers and babies in remote communities provided the model for the Frontier Nursing Service in Kentucky whose nurse-midwives famously covered the Appalachian Mountains on horseback.
It is a remarkable story of truly remarkable women.
The nurses and midwives were part of the Highlands and Islands Medical Service (HIMS), a forerunner of the NHS set up 35 years earlier which provided state-funded comprehensive care for more than 300,000 people across half of Scotland's land mass.
Prior to 1913, medical and nursing care in such remote communities was patchy at best - and non-existent at worst.
Within 20 years, that had all changed. Resident surgeons and physicians had been appointed to hospitals, the first air ambulances were taking patients to the mainland.
Above all, there was for the first time, a high quality service from family doctors and district nurses and midwives. They worked closely together proving a model for the future NHS.
Fees, when charged, were minimal. Uniquely in pre-NHS Britain, there was affordable treatment to women, children, the poor and others not covered by the existing national insurance scheme.
Sir Leslie Mackenzie was the main driving force behind the HIMS. A socialist and friend of Beatrice and Sidney Webb, he was medical member of the Scottish Board of Health (a post which later became Chief Medical Officer for Scotland). He and his wife Helen, were leaders in promoting better nutrition and care for mothers and young children.
It was to the Mackenzies that the American pioneer Mary Breckinridge came to in August 1924 to see for herself how nurses and midwives worked in the Highlands and Islands Medical Service.
Breckinridge was born into a rich and influential family. She suffered the tragedy of losing both her children before they reached five. Trained as a nurse, she went to France in 1918 working for the American Committee for Devastated France.
Earlier International aid by the women's suffrage movement had supported the Scottish Women's Hospital Unit at Royaumont set up by Elsie Inglis, a close friend of Helen Mackenzie.
In France, Breckinridge recognised the value of trained midwives - then virtually unknown in the United States. She qualified as a midwife at Woolwich in London then fixed her sights on the journey north. It was to change her life.
"Sometimes an experience is so deeply creative that you respond to it with everything that you have, not only in retrospect but at the time. When I went to Scotland in mid-August of 1924 to make a study of the Highlands and Islands Medical and Nursing Service, I knew that weeks of enchantment lay ahead of me, but I could not know until it happened what it would be like to enter a strange country and feel at once that I had come home" she later wrote.
Sir Leslie greeted her warmly in Edinburgh and gave her a letter of introduction for her travels.
Her next port of call was the Scottish Headquarters of Queen Victoria's Institute for Nurses. "Queens Nurses" provided the backbone of the HIMS. Highly trained in general nursing, many had additional qualifications in midwifery.
Perthshire was the next stop. Like Hertfordshire in England, it had a well developed nursing association structure. Much of this was due to Kitty Murray, Duchess of Atholl, a nurse and member of John Dewar's committee whose report in 1912 led to the establishment of the HIMS. Murray later became the first female MP in Scotland and the first female minister in a Conservative Government.
It was called HIMS but the Scottish Board of Health which provided its administration also embodied in HER. Unusually for that time, it purposely had a female board member - Muriel Ritson, a high-flying civil servant.
Breckinridge noted the high level of local autonomy and flexibility between the central body at the Scottish Office in Edinburgh and local committees. Thus state funding was much higher in the sparsely populated Outer Hebrides than the more prosperous mainland counties.
On her return to Kentucky, Breckinridge set about putting into practice what she had seen in Scotland. She had taken meticulous notes - 11,000 words in various notebooks.
She was appalled at the number of American women who died in childbirth. Death rates were four times as high as those looked after by the Queen's Nurses in Britain.
America had forged ahead in nurse education. The University of Texas had established a chair of nursing in 1895. Glasgow Royal Infirmary had earlier set up a nurse training school which itself inspired the school of nursing at Yale.
But in midwifery, there was strong resistance to the European model of midwives being responsible for normal births with obstetric help at hand when required. In the USA, the medical model not only prevailed but was enforced - all births should be under the supervision of obstetricians.
Breckinridge wanted to challenge this - particularly in remote areas where there were no physicians, never mind obstetricians, to deliver babies.
What became the Frontier Nursing Service held its first meeting in May 1925. Scottish origins were evident in the choice where they would start - Leslie County, one thousand square miles with 15,000 people and no doctor.
As in parts of the Highlands, births and deaths had gone unrecorded for years. To demonstrate what nurse midwives could do, they needed a statistical base.
Breckinridge contacted Sir Leslie and tracked down Miss Bertram Ireland, who had acted as secretary to his inquiry on the Physical Welfare of Scottish Mothers and Children.
Miss Ireland had two further essential qualities. She could ride horseback and she could take a nickname. The Frontier Nursing Service also pioneered the now blokeish practice of pen names for their staff.
"Ireland from Scotland" became the first of many. Riding from the nearest railheads Krypton or Hazard was the first test for anyone - at least 20 miles across mountains and fording rivers and streams.
In June 1925, Breckinridge noted: "She has begun her work on Hell-fer-Startin' Creek and Devil's Jump Branch - really. She is blistered, sore, stiff, and undaunted"
Others followed in her wake. In some women, it offered an intoxicating challenge. Riding was essential and the first test came in the initial journey from the nearest railheads at Krypton or Hazard - at least 20 miles across mountains and fording rivers and streams.
Most were British or Irish. In the absence of any training in the USA, some American nurses joined having taken midwifery courses in Britain.
Each nurse-midwife had her own patients - desperately poor families scattered off the mountain trails. As in the Highlands they offered a complete nursing and public health service as well as midwifery.
Annie P. Mackinnon from Skye was one of early recruits. She had served with the French Flag Nursing Corps during World War One. She was awarded the Croix de Guerre for continuing to care for the sick and wounded under enemy fire during the retreat from Aisne in the early summer of 1918.
Inevitably, she was given the name "Mac". She would joke with her Irish colleague Hannah "Nancy" O'Driscoll from Skibboreen, when playing Harry Lauder on the gramophone about what songs might be played in heaven.
The work was punishing and hazardous. The first to die was Nancy. She had ridden out to care for a mother but stayed with her despite taking ill herself. By the time she got back, Nancy's appendix had ruptured. She was only 35.
The FNS modelled some of their equipment on that of the Royal Canadian Mounted Police. The Mounties always got their man but the Frontier nurse-midwives never left their woman once she had started labour. Others suffered serious injury. Mary Breckinridge broke her back in a fall from her horse in 1931.
Equally hard, particularly when the depression and drought hit Kentucky was the constant need to raise funds. Unlike HIMS, there was no government money. From the outset, Breckinridge used all her social networks to enlist. Committees were established in major US cities to raise funds. Prominent patrons show funded the clinics included Mrs Henry Ford.
Publicity was essential to keep up FNS profile. Breckinridge's cousin, Marvin, was the first FNS courier - young women who rode with the nurse midwives and tended to basic tasks like building up the fire or looking after the other children.
Marvin later made a film of the service and became the first female colleague of Ed Murrow (of Good Night and Good Luck fame) reporting the London Blitz for the CBS network.
The major early landmark was building the first FNS hospital - at Thousandsticks Mountain in Hyden. There was only one choice to perform the opening ceremony on June 26 1928.
Sir Leslie, then 66, and Lady Helen Mackenzie were delighted to oblige. Neither could ride and new buckboard was tested by "Mac" in advance. It was well she did. The 22 mile journey from the railroad involved teetering over precipices in a violent rain storm and fording the swollen Kentucky River.
He waxed lyrical in his address, later published in the Lancet.
"It is a story full of adventure, sacrifice, passionate enthusiasm and splendid initiative. When, some years ago, Mrs Mary Breckinridge came to us in Scotland to see how we had faced a similar problem in medical service and nursing, we were filled with a new sense of significance of the work we had tried to do in the thinly peopled and difficult areas of Scotland.
"When, therefore, I was invited by the Frontier Nursing Service of Kentucky to give verbal form to the dedication of the hospital and nursing system now established in these mountains, I felt indeed, a glow of supreme satisfaction that our work in Scotland had found an echo in the great spaces and mountains of an American Commonwealth. The invitation was a call of the Highlands to the Highlands. It is a symbol of kinship in feeling and outlook. It is the lightning spark that reveals the essential unity of our culture ..
"The beacon lighted here today will find an answering flame wherever the human hearts are touched with the same divine pity. Far in the future, men and women, generation after generation, will arise to bless the name of the Frontier Nursing Service"
The FNS did develop attracting increasing interest from North America and beyond.
By 1932, an external audit of its first 1000 births showed not a single maternal death resulting in pregnancy or labour.
"This study shows conclusively that has in fact been demonstrated before, that the type of service rendered by the Frontier Nurses safeguards the life of the mother and babe. If such service were available to the women of the country generally, there would be a saving of 10,000 mothers' lives a year in the United States, there would be 30,000 less still births and 30,000 more children alive at the end of the first month of life."
The nurse-midwives in the Hebrides would have been very proud of them.