“If you’re coming in to talk to Virginia, you might as well have lunch.” My mind’s eye raced to wild salmon carpaccio sent up from Le Bernardin – something fitting for the 50th anniversary of a major architect of the American art world, a woman of stunning achievement on two continents. Could I take notes and negotiate a vintage Coteaux du Layon at the same time? The gallery assistant read my hesitation and clarified: “She always sends out for chicken salad. You can share half a sandwich.”

It was a lively lunch with an engaging, unpretentious woman whose remarkable odyssey began in 1954, when she put $1 down to take over the lease of the Korman Gallery, a small uptown space between a lampshade vendor and a hairdresser. A cooperative established by a fellow graduate student at NYU’s Institute of Fine Arts, its members included the painters Pat Adams, Lester Johnson, Clinton Hill, and Vincent Longo. They formed the initial core of Zabriskie Gallery.

Ms. Adams, down from her Vermont studio with her husband, was in the gallery while I was there, and she joined the conversation. A familial tag team, she and Ms. Zabriskie enlivened the gallery’s history in ways more subtle than the public record allows. The relationship between these two women – a mix of intimacy, hardheadedness, enduring respect, and gratitude – reflects the special character of the gallery itself and Ms. Zabriskie’s unique contribution to American art in the second half of the 20th century.

Without financial backers or a client list, Virginia Zabriskie entered the art world with only a $1,000 bequest from her grandmother, her own optimism, and a passion for art. Sales were sparse in the beginning. At the outset all she could offer her artists was a dividend if the gallery earned more than $800 at the end of the year. As Ms. Adams recounts, there was no profit: “No one expected to live from the sale of paintings; one hoped to make strong art.” Robert Schoelkopf, later to open a prominent gallery under his own name, became a partner for a few of those early years. Asked how that relationship began, Ms. Zabriskie laughed: “He was my only client!”

By the 1980s, though, Zabriskie Gallery had three spaces: two in New York (paintings featured at 724 Fifth Avenue, sculpture at 41 West 57th Street) and one in Paris. Galerie Zabriskie/Paris, devoted to photography as a collectible (not simply an adjunct to printing), opened in 1977, at the same time as the Pompidou Center. It was the first gallery of its kind to combine exhibition space with a bookshop dedicated to the medium’s history, and it soon became a gathering place for photographers themselves.

Ms. Zabriskie promoted French photography in Paris, organizing landmark exhibitions of work by such 19th-century figures as Eugene Atget and Nadar, at a time when there was little interest in it among Europeans: “Putting on shows was the most important way for me to develop a market for photography,” she explained. Artistic exchange became the keynote of the trans-Atlantic venture, introducing American photographers (including Diane Arbus, Alfred Stieglitz, Walker Evans, Paul Strand, and Berenice Abbott) to Europeans, as well as giving artists such as Brassai, Brancusi, Claude Cahun, and Georges Hugnet their first American exposure.

By the time it closed after 22 years, the Paris gallery had set precedents and created markets for work where none had existed, an achievement that earned Ms. Zabriskie the Medaille de la Ville de Paris in 1999. Organizing more than 800 exhibitions here and abroad, she has been crucial in expanding acquaintance with Dada, Surrealism, and early modernist American painting and sculpture, no less than photography. Asked what factors (apart from losing her Paris apartment) led to her decision to close the gallery, Ms. Zabriskie had her answer ready: “My grandmother always said, ‘When the party is good, go home.’ ” It is a charming response, whether or not it tells the whole story.

At one point, Ms. Zabriskie left the room, returning in minutes with a bulging folder stuffed with a half-century’s correspondence from Ms. Adams, some of it typed on fragile, browned onion-skin, some penned with hand-embellished margins. “I keep every letter my artists send me,” she told me. She turned notes over with a protective pride that signaled more than affection. It was the mark of someone who understands the humane value of preserving the present as patrimony for the future.

The woman who cherishes her artists’ correspondence is the same one who, in 1993, chose the University of Delaware as the major repository for more than 1,400 works – mostly on paper (including several hundred studies of Isadora Duncan) – by Abraham Walkowitz (1878-1965), the Russian-born American modernist. Over the years, she held multiple Walkowitz shows and purchased many works from his estate; much of that personal collection was donated to the university archive.

Her ambition to conserve is characteristic. Ms. Zabriskie has never been a dealer – a merchandiser – in the usual sense. “Although the gallery relies on making sales, it has never dictated my choices. I depend solely on what I feel about the artwork,” she said. When the art world was in thrall to Abstract Expressionism, she went her own way, preferring artists who evaded stylistic categories. Admirers of Elie Nadelman (1882-1946), only one of the early modernists she has rescued from neglect, owe the recent resurgence of interest in him, in part, to Ms. Zabriskie’s critical intelligence and adventurousness. (Using clients’ money, she once purchased four Nadelman sculptures at $18,000 each from Helena Rubenstein’s estate; she needed to borrow a quarter, though, to pay her fare home.)

Coaxing sensibilities and exercising discernment, both scholarly and aesthetic, is a vocation before it is anything else. Ms. Zabriskie’s entrepreneurial acumen serves a strong sense of responsibility, for art of the recent past and for all work she chooses to exhibit. Asked how the concept of artistic conscience might be applied to dealers, she described herself as having been “a handmaiden to the arts.” It is a gracious term, one that fits. Ms. Zabriskie’s instinct for stewardship, not market moves, has distinguished the gallery from its inception.

The progress of Zabriskie Gallery coincided with unparalleled postwar prosperity. Can today’s young dealers achieve as much with no financial support behind them? “I doubt it,” she told me. Her answer hinged on the evaporating pool of older, unappreciated but significant work and, with it, opportunities for what she calls “archeology”: digging for historically interesting but neglected artists (as she did for Nadelman, Walkowitz, and Arnold Friedman) or taking advantage of dramatic finds (such as the 40 original Stieglitz prints that turned up in a Saks Fifth Avenue box). These permitted her to finance her own commitment to living artists.

“It’s all been bought up by large institutions, the museums,” she said of the situation. “Today’s dealers have to sell what’s on the wall; there are fewer alternatives.” Besides, rents were more affordable then and “costs closer to your life situation.” And with fewer galleries, it was much easier to get a review.

“Sometimes I wish I had responded more to market trends,” Ms. Zabriskie said. “What money I have came from those Stieglitz prints.” It was not stated as a regret, simply an acknowledgment of economic realities. What plans exist for the gallery after Ms. Zabriskie retires? She dropped both palms decisively onto the desk: “I have no plans to retire. I’ve given myself anniversaries before. I’ll give myself another. This is not the last.”

Lunch over, we joined in that universal female ritual of clearing the table. Carrying paper plates and aluminum foil to a work sink, I confessed my initial luncheon fantasy. Her response was quick: “You have no idea how much art gets bought and sold over lunch and a few drinks in this town.” She gestured to a painting and added, “But everything I’m selling is right here on the wall.”

In other words, Virginia Zabriskie is not selling borrowed glamour or anything you cannot see. And everything visible is an object of love.

“New York/Paris: Season 1980” at the Zabriskie Gallery until April 16 (41 E. 57th Street, 212-752-1223).