Christopher Leaver was only two-and-a-half years old when he made the perilous Atlantic crossing in June 1940, with torpedoes a constant danger. The future Lord Mayor of London remembers “our cabin flooding on the way out”, but it was nothing too serious - “someone left the bath taps running and we paddled in the water. Then, when I revisited Virginia in 1982, I recognised my old bedroom at Clover Croft.”

The young Christopher, his older sister Gillian, and 10 other children aged between 20 months and 12 years spent two years of the war at Clover Croft, a white Southern-style house with traditional verandah and pillars in Warrenton, Virginia. They were a ready-made family unit headed by Auntie Bee and Auntie Amanda, two 30-year-old Englishwomen. The children, whose parents were mostly stationed overseas, had been boarding with the aunts at their farm near Bexhill, East Sussex, when war broke out. Amanda was a trained nurse; Bee, my father’s sister, had first trained as a singer but enjoyed working with children. She was the driver and housekeeper and looked after the hens and pony.

First the aunts took the children to Devon, but they were bombed out in three weeks. The US military attache, whose daughter spent summers at the farm, looked for ways to get them out of Europe. He persuaded Eugene Meyer, a banker and owner of the Washington Post, to be their sponsor. The aunts and their charges swapped their gasmasks for lifejackets and sailed for Halifax just three months before another evacuation ship, the City of Benares, was torpedoed. Seventy-three children died and evacuations by sea stopped. By then 2,700 official and 11,000 private evacuees had been sent to Canada. The Clover Croft children, a self-contained group of 12 “little refugees” with a high-profile sponsor, became instant celebrities. Their experience was not that of the typical refugee child. Meyer had furnished the rented house in the Blue Ridge Mountain town down to the last doll and tricycle and hired a cook, laundress and maid. Despite their relatively well-heeled backgrounds, the children were overwhelmed by their opulent new surroundings: refrigerators, big car, no rationing. “We have arrived in fairyland,” writes Auntie Bee under the pen-name of Angela Pelham, the young narrator who tells the children’s story through fictional letters to her parents in India. The title, The Young Ambassadors, was inspired by Lord Lothian, the British ambassador to Washington, legal guardian to all British children in the US and a regular visitor at Clover Croft. Angela Pelham writes: “He told us how fine it was for England to have a little colony of young people like us in Virginia, and we were all just as much ambassadors as he was.”

The Duke and Duchess of Windsor visited Warrenton - the Duke said he wanted children just like them - William Hickey of the Daily Express also came to call and they were invited to the White House. Gillian Leaver, now Gillian Kelly, recalls: “We had a wonderful Easter tea at the White House, with Eleanor Roosevelt as our hostess. We were each given a magnificent sugar egg with a different picture inside.

“I have a clear memory of my father, who was a naval doctor, coming in on his ship to Washington. Christopher and I were brought up to Washington to meet him and there was much press coverage. We were even on the Pathe News in England and my mother, who was an ambulance driver, went to watch us at the cinema.”

The aunts battled to provide a stable home routine at Clover Croft, and ran a tight ship on manners, clean clothes and English pronunciation. “For the Duke and Duchess of Windsor’s visit there was such a to-do and we all had to look our best,” Gillian says. “Great emphasis was always put on cleanliness and if ever the boys dirtied their clothes, we girls had to take off our frilly pinafores and give them to them to wear.”

Arthur Jenkins, MP for Monmouth and private secretary to Clement Attlee, came at Christmas to sing carols and soothe the aunts, who wanted to keep the children in touch with English ways but were dependent on their US benefactor. Their first serious differences of opinion with Meyer concerned education. He insisted on the school-age children attending the Warrenton public (state) school (they had gone to independent schools in Britain). He believed that “their parents would be down to rock bottom by the end of the war and they must get those swell ideas out of their head now”.

The aunts were worried about low standards in schools in the southern states and were also concerned that their charges would become “too American” (they had brought along a British-trained governess, Laila Dewidar - known as “Doodah” to the children - for the younger ones). Susie, another Clover Croft child, remembers being scolded when she was five: “I was sent to ask Violet, one of the kitchen staff, for some oranges; the trouble I got into when I announced on my return, ‘Vi’let, she say dere ain’t no oranges, Mam!’ ” If the sense of responsibility, the scrutiny of welfare committees and the determination to keep up standards of discipline and good manners were exhausting, the aunts were rewarded by the kindness of friends and neighbours, who offered a seaside house so the children could recover from chicken pox away from the greenhouse heat of Virginia. Through Angela Pelham’s letters, Auntie Bee recorded the highs (picnics, ice-cream sodas, the Empire State Building) and the extreme lows (homesickness, worry about families, being constantly on parade, being conspicuous at school).

The Clover Croft household broke up when America entered the war in 1942. Gillian and Christopher’s mother took them to join their father in the West Indies. Those whose parents wanted them to stay in the US moved to an institute for immigrant children in New York and went to elementary school in the Bronx. Six came home with the aunts, who by then wanted them to share their peers’ experience of rationing and blackouts. They rented a house in Oxshott, Surrey, where they had to manage without servants and were berated by an air-raid warden for hanging out nappies during the blackout. Auntie Amanda, now 91 and living in Sussex, recalls: “We missed the American way of life, we had been spoiled.” But her clearest memory is of “how thoroughly glad we were to be home”.

Like most children who survived the war, the Clover Croft group had to make up for disrupted schooling. Sir Christopher failed his Common Entrance but was still allowed into Eastbourne College in Sussex. He became a wine merchant in the City and, in 1981, Lord Mayor. Gillian trained as a nurse and had two children.

Robert Hicks, who was eight years old in 1942 and who stayed on in New York for three years, fared worse educationally. “I was four years behind in maths and other things though reading and writing were OK. I could not get into the local village school. I was tutored for about a year.” At 14 he was accepted as a day-boy at Taunton School, Somerset. He returned to the US as an adult and now lives in California. “Certainly my five years there influenced my return.” Another Clover Croft girl, called Tessa in the book, settled in Canada and also became a nurse. The rest (one died aged 14, another at 34) are happy with their lives in England, but still confess to wanderlust.

‘The Young Ambassadors’ by Angela Pelham (Andrew Dakers, 1944) is out of print. A dramatisation by Jennifer Curry will be repeated on Radio 4 at 2.15pm on September 2. In the book and play, the children’s names were changed, but in this article the children have given permission for their real names to be used.