He may never have read the book but his wife, Sandra, picked it up one evening and began to read it. It was not long before she voiced her opinion. Turning to her husband, she said, ‘You gotta read this – and if you don’t publish it, you booby, I’ll kill you!’

In the face of such compelling words, he had little choice but to read it himself. With every passing chapter, his excitement grew as he began to realise that he was enjoying the work of a master story-teller; by the time he had finished reading the book, the germ of an idea had become established in his mind. Could this be the author he had been looking for?

As the weeks went by, the idea grew into a firm resolve that the rest of the United States was going to read the book, too. In the years to come, he would have cause to bless the forceful advice from his wife on that memorable evening in New York.

My family has always admired Tom McCormack for his unwavering determination in getting that first book published. He was so convinced that he had a potential best-seller, he was prepared to stake his whole career on its success. He saw this man, James Herriot, as the possible saviour of his ailing firm – but he had some enormous obstacles to overcome.

The first was that the book was too short; if he were to win over the American public, he needed a book twice the length. Early in 1971, however, his prayers were answered. He contacted Claire Smith of the Harold Ober agency in New York – the American associate of the David Higham agency in London; she too had been trying to interest American publishers in If Only They Could Talk, but with little success. When Tom McCormack approached Claire Smith, she told him that she had heard from London that the vet had completed another book. This was exactly the news that Tom had been waiting for. As soon as he could, he obtained a copy of the book from the David Higham agency in London. After enjoying it as much as he had the first, he saw that the two books could be combined into one volume.

Tom still had a problem; he wanted the book to have a more definite ending – something that the second book, like the first, did not have. Through David Higham Associates, he contacted Alf, very tentatively asking if he could write a finale to the book – one where James Herriot marries Helen, in order to give the story a satisfying conclusion. He wondered what the strange vet in distant Yorkshire would make of such a request, but he was not to be disappointed. Alf, intensely excited at the prospect of his books being published in America, was only too happy to oblige and, in Tom McCormack’s words, ‘He wrote three chapters, gave us a wedding, and an ending that chimes as gloriously as The Sound of Music’

Rosie proposed a title for this new book, ILL Creatures Great and Smallwhile, coincidentally, someone at St Martin’s Press had come up with the title ALL Creatures Great and SmallAlf was keen to use Rosie’s title, but Tom preferred to adopt the more traditional title. There was no argument and Tom got his way; these were exciting days and, bemused as he was by the enthusiastic approach of his new-found publisher in America, Alf was willing to cooperate in every way that he could. In later years, when he had become an established best-selling author, he had the confidence to stand his ground when Tom wanted to alter parts of his stories, but in those early days, he toed the line.

On 17 September 1971, as Alfred Wight signed the contract with St Martin’s Press for All Creatures Great and Smallhe could hardly believe his good fortune; but no one could have anticipated just how momentous that signature would turn out to be.

1972 was a hectic year for Tom McCormack, during which he had to overcome another huge hurdle – convincing everyone at St Martin’s Press that the memoirs of the first two years in the professional life of an obscure vet in faraway Yorkshire could possibly become a best-seller. Having finally persuaded his colleagues, he next had to convince the booksellers to support it. He began a ‘campaign of enticement, intimidation and force-feeding’.

He threw everything into the marketing of the book. Six thousand copies of the first chapter were printed and given away to selected librarians, bookstores and reviewers. A money-back guarantee was offered to anyone who was not delighted with the book, little ivory animals were sent to major bookstores as a gimmick to draw their attention to the book, while Tom wrote personally to all the major reviewers. In his letters he described the reading of the book as a ‘rich and joyful experience’, while saying of James Herriot and his work, ‘he conveys a love of life that seems thoroughly justified. No book I’ve worked on in fifteen years of publishing has given me more pleasure.’

Despite this energetic marketing campaign, advance sales were disappointing, with only 8,500 copies of the book in the shops two weeks before publication. Tom, however, remained convinced that if only a leading reviewer would read it, like it and give it a good review, then the book would take off. The vast American public, he felt sure, needed only a taste of All Creatures Great and Smallbefore they would want more; all he asked was that someone would give it to them.

This was a brave venture from a man who had put his whole future on the line. The failure of this book – on which he had pinned so many hopes – could have serious consequences for both himself and his company. As publication day approached, Tom McCormack crossed his fingers and waited.

All Creatures Great and Smallwas published in November 1972 to a profound silence from the major reviewers. Tom was bitterly disappointed. Was there anyone else in the United States of America, he wondered, who shared his appreciation of the writing of this man, James Herriot? Was he the only one in the vast publishing industry who saw the author’s potential? Had he made a massive mistake in risking his future on the work of the unknown Yorkshire veterinarian? He waited, desperately, for a tiny glimmer of hope.

It was not long before his questions were answered. On 12 November, while reading the Chicago Tribunes‘Sunday Book World’, he felt a surge of excitement. On the front page of this enormously influential newspaper was a review of James Herriot’s book. The review, by a man called Alfred Ames, radiated superlatives.

‘If there is any justice, this book will become a classic of its kind.… With seemingly effortless art, this man tells his stories with perfect timing. Many more famous authors could work for a lifetime and not achieve more flawless literary control.’

This was the break Tom McCormack had been waiting for. This one review set in motion a host of others. Anatole Broyard wrote in the New York Timeson 14 December: ‘James Herriot, a British veterinary surgeon, is one of those rare men who know how to appreciate the ordinary … He’s a veterinarian, that’s what he is, and when his right arm is free, he’s a helluva writer as well.’

By January 1973, the reviews were pouring out. The Houston Chronicleheaded its review: ‘Superlatives aren’t enough. This book is absolutely super, a rarity, magnificently written, insightful, unforgettable. If you have ever loved a friend, human or otherwise, this is the book for you.’

These reviews provided the spark to ignite a sales inferno that swept across the United States of America. The book was on Timemagazine’s best-seller list by early January 1973, and that of the New York Timeslater that month. James Herriot’s fame soon spread from coast to coast and, within one year, his book had been selected by book clubs, serialised in magazines and published as a condensed book by Reader’s Digest. Within a few months of publication, the paperback rights were bought by Bantam Books, and after two hundred thousand were sold in hardback, a further million followed in paperback – 1973 was a truly phenomenal year, for both James Herriot and Tom McCormack.