With their substantial fortunes and slender frames, Pat Buckley and her old friend Nan Kempner were thought to have inspired Tom Wolfe’s depiction of that Manhattan phenomenon, the social X-ray, in his novel of the 1980s, The Bonfire of the Vanities.

She would say she was “just a simple country girl from the woods of British Columbia” but there was more to Mrs William F. Buckley Jr than that. Born to and married into privilege, Pat Buckley’s life combined noblesse oblige and haute couture with a genius for raising money and an unswerving devotion to her husband, one of America’s leading conservative thinkers.

She was unstuffy, a rare quality among the upper reaches of the Upper East Side – a friend described her as a combination of Auntie Mame and Calamity Jane – and she never neatly fitted the role of a conventional grande dame, even if, at just under six feet tall, she had the physical presence.

Patricia Alden Austin Taylor was born in Vancouver, one of the three children of Austin Cotterell Taylor, a self-made industrialist who wrung his fortune from timber and mining. Her mother, Kathleen, was a beauty, but Pat claimed to look, she said, “exactly like my father”. She was educated at home and at Crofton House School. She hunted and shared her father’s love of horses. One of them, Indian Broom, raced against Seabiscuit.

Her mother was a civic leader and, at 13, Pat was a volunteer at a children’s hospital in Vancouver. Seven decades of voluntary hospital work would follow. Her education continued at Vassar College, in New York State, where she shared a room with Patricia Lee Buckley, daughter of the conservative Roman Catholic oil baron, William F. Buckley Sr and sister of William F. Jr (WFB).

Patricia asked her dashing brother, then at Yale, to accompany Pat to a dance after her original partner broke a leg. A year later, after Pat had returned to Canada, WFB visited her and three days later they were engaged. They married in Vancouver in 1950, after WFB’s graduation. Mrs Taylor, who initially thought that in marrying a Catholic her daughter was “marrying down”, was determined to ensure sobriety among the groom’s party. She issued the directive “No nips before nups” with a suggestion (seriously taken, given Mr Taylor’s influence) that any lapses would lead to drafting into the Canadian Army and service in Korea.

Henceforth Buckley would describe her chief role in life as “Bill’s wife”. For nine months in 1951 WFB worked for the CIA in Mexico where, Pat claimed, if you wanted to know anything, “you asked the Israelis”.

In 1952 they settled in Connecticut, the state where his family had always spent the summer. They bought a waterfront house overlooking Long Island Sound at Wallacks Point, Stamford, and it was to be home for the rest of her life. WFB sailed and she gardened, often in a bikini. She claimed, unconvincingly, that the only thing she did really well was to run a house. Apart from Stamford, there was a Park Avenue maisonette, vividly transformed from the days it belonged to Dag Hammarskjöld, where she served dinner twice a month to the editors of her husband’s magazine, National Review. And every winter the Buckleys rented Château de Rougemont near Gstaad. The King and Queen of the Hellenes, the Galbraiths, the “High Life” columnist Taki, the designer Valentino, Roger Moore and her favourite, David Niven, would join the Buckleys for drinks, foie gras and peanut-buttered bread.

Her wit could be as biting as the weather outside. Once, after J. K. Galbraith had brought Teddy Kennedy to visit Rougemont, the Senator asked if he could borrow a car to return to Gstaad. Buckley retorted, “Certainly not – there are three bridges between here and Gstaad.”

She called herself an Arab wife. She was devoted beyond question, but silence did not come easily. Good form and old-world courtesy were also important but once, finding herself being lectured at by a mayor of New York on the evils of secondhand smoke, she blew a puff at him and asked: “Mr Mayor, may I smoke in my own house?”

With her fellow sylph, Nan Kempner, she raised some $75 million for the Memorial Sloan-Kettering Cancer Centre. New York University Hospital and St Vincent’s also benefited from her fundraising, as did victims of Aids and Vietnam veterans. “I’m not a social arbiter,” she once said. “I am, to put it in really vulgar language, a moneyraiser. I’m a moneyraiser for things I believe in.”

For 17 years she chaired the annual benefit for the Metropolitan Museum of Art’s Costume Institute and raised about $34 million. For four decades she appeared in the pages of Women’s Wear Daily, Harper’s Bazaar and Vogue. She tended to choose American designers, such as Bill Blass, Halston and Oscar de la Renta. Unlike a number of those who currently inhabit the haute couture scene, she bought her own clothes – though sometimes at a discount. She had no need for a publicist or stylist. She would generally do her own hair, barely taming it with the aid of dime-store Dippity-Do, and she applied her own make-up – dramatically encircling her wide eyes with eye shadow. Her abiding brio and chic were recognised with her induction into the Fashion Hall of Fame.

With her beloved King Charles spaniels at her feet and a cigarette invariably in hand, she looked back on the 1970s with affection. Although she admired Michael Bloomberg, the Mayor, she tired of the city she had conquered. “New York is dark now. Dark.” It may well be less lively with her passing.

Her husband and their son, Christopher, a writer, survive her.

Pat Buckley, fundraiser and socialite, was born on July 1, 1926. She died on April 15, 2007, aged 80