Two decades ago this week, Jacqueline Bouvier Kennedy Onassis died at age 64. On May 19th, 1994, a nation mourned a former first lady who had become not just a style icon, but a national symbol of strength and courage.

November 21, 1963: In San Antonio, Texas, in a white suit and her signature pillbox hat.

She was a book editor who refused to tell the greatest story of all—her own. And so, what I know of her, I know mostly from pictures, and these provide the most vibrant clues to the gentle mystery of her life.

Circa 1971: The book’s cover photo shows Jackie walking on Madison Avenue.

A new photo book, New York Jackie, documents her post-White House life in the Big Apple, where she made her home after JFK’s assassination. From jogging in Central Park to attending galas at The Met, Jackie Kennedy Onassis’s style never failed to impress—it was simply natural and effortless. Her modernized fashion sense introduced women of her generation to relaxed pants, pillbox hats, and oversized sunglasses, creating an iconic look that is still admired today.

1979: Attending the Costume Institute Gala, “Fashions of the Hapsburg Era,” at the Metropolitan Museum of Art.

In the beginning, Jacqueline Kennedy was to express her nature, declare her breaks from tradition, exclusively through the clothes she wore. If she had one principle of dressing, it was to insist on fine fabrics and superior craft. She told a friend, “It doesn’t matter what you wear as long as it’s quality.”

December 22nd, 1969: Her elegant looks and regal bearing elevated even the simplest clothes.

Consider, for example, the sleeveless, white Oleg Cassini gown she chose for the inaugural gala—and what a departure that gown was from the beaded, the bugled, the stuffy taffeta, the stiff crinolines, the tight girdles and tight curls of Mamie and of Bess. Jackie’s boxy Chanel suits were defiantly French, and how elegantly they mocked Pat Nixon’s Republican shirtwaists and that famous fatigued cloth coat.

January 20th, 1961: The First Lady brought youth and glamour to the White House. Her Oleg Cassini hat and coat were hallmarks of the “Jackie Look.”

Rumor then had it that Jackie Kennedy spent $30,000 a year on clothes. This business of looking lovely was, for a while, a consuming objective (later she’d adopt another equally aesthetic pursuit—the restoration of the White House).

In Manhattan, 1970

The last time I saw a famous grown woman in unabashed pink it was Jackie: Still etched in national memory is a special shade of rose, belonging to a Schiaparelli suit worn in a Dallas motorcade. By morning’s end the suit was stained with her husband’s blood, but in spite of Lady Bird Johnson’s pleas, Jackie refused to shed it. The soiled garment was—for her, for us—forever a symbol of the tragedy. This was the last piece of herself she would ever choose to share with her public.

September 2nd, 1970: Her trademark glasses were widely copied.

It is easy to understand Jackie’s desire to remain apart, easier still to recognize her desire to be private. After her marriage in 1968 to shipping tycoon Aristotle Onassis—a day captured in wedding pictures of her wearing white hair ribbons, improbably girlish and gay—her clothes grew protective. More and more, she showed up behind mammoth sunglasses, her dark hair hidden beneath an Hermes scarf.

January 3rd, 1972: Her Hermès scarves hid her hair, not her style.

In the mid-seventies, Jackie launched a new life as an editor—first at Viking Press, then at Doubleday. Oh, the Jackie style was still in evidence, of course, consistent even as her life continued to change. Now there were piles of skinny tees in every color and tight trousers, soft Valentino dresses, lovely cashmeres, and a glorious green crepe Carolina Herrera dress she wore to daughter Caroline’s wedding in 1986.

July 18th, 1986: A green crepe Carolina Herrera dress for her daughter Caroline’s wedding.

Though her taste was timeless, she was not. Her children now had grown. Pictures of her seemed rarer, more fleeting, more fragile: the delicate mother jogging, elegant even in sweats and thin as a fading hope; then the delicate grandmother jogging, thinner still.

Walking in Manhattan on the Fourth of July, 1984

“In many ways, Jacqueline Kennedy Onassis was a quintessential New Yorker,” Nan A. Talese, senior vice president of Doubleday, writes in the introduction. “She was gracious, elegant in the simplest way, and had a style that I will always think of as New York.”