Rosalynn Carter, who died on Sunday at age 96, was rarely included on any list of best-dressed first ladies. She was not generally called “stylish” or “trendsetting.” She did not play the White House dress-up game, at least as designed by predecessors such as Dolley Madison and Jackie Kennedy. Most of the time, she seemed to actively reject it.

But that does not mean Mrs. Carter did not fully understand the power and political use of clothes, or how to strategically deploy them during her time in Washington. In fact, it is possible to see her time as first lady as a blueprint for an alternative approach to image-making that is still being used today.

Starting with Mrs. Carter’s declaration, after Jimmy Carter was elected in 1976, that the one item she would be taking with her to the White House from Georgia was her sewing machine. As a symbol, it was a succinct message to anyone listening that this was, indeed, a recession-era administration that would prioritize economy and accessibility. It was also a nod to her own folksy roots as the daughter of a dressmaker. And it set the tone for what came next — which was the greatest dressing scandal of the administration.

That took place during the 1977 inauguration, after the Carters had made history by becoming the first first couple to walk rather than ride during the inaugural parade. (Mrs. Carter’s stroll-appropriate high-neck teal cloth coat by Dominic Rompollo, a New York designer, knee-high leather boots and leather gloves all look notably modern.)

Instead of wearing a new gown to the inaugural balls, Mrs. Carter wore the same caftan-like, high-neck, gold-embroidered blue chiffon dress by Mary Matise she had bought and worn to Mr. Carter’s 1971 inauguration as governor of Georgia.

Shock and horror was the general reaction. Used clothes at the inauguration! Despite the fact that Mrs. Carter added a new gold-trimmed cape to gussy it up a bit, also by Mr. Rompollo and purchased through Jason’s, a store in Americus, Ga., The New York Times labeled the dress “old” and called Mrs. Carter a “sentimentalist” for wearing the frock again. The new first lady’s support for Seventh Avenue was questioned as the fashion industry humphed its disdain, as was her ability to represent the United States with befitting glamour on the world stage — despite the fact that glamour had never been the Carters’ sell in the first place. Down-home morality was more like it.

To that end, the inauguration dress and the values it represented established the precedent for Mrs. Carter’s stint in the White House. She continued to shop off the rack — another favorite boutique had been A. Cohen & Sons, likewise in Americus — and she decorated the White House for Christmas with pine cones, peanuts and egg shells.

But she also continued to break sartorial rules, becoming the first first lady (yet another in her litany of firsts) to establish an office in the East Wing, not to mention the first to carry a briefcase to work every morning. A briefcase!

Perhaps understanding that such an obvious sign of her more active advisory role in the administration might be as startling to the general electorate as her shopping her closet, Mrs. Carter was careful to pair that potentially controversial office accessory with more traditional shirtwaists, often detailed with pie-crust collars or other more classically feminine frills, often in colors like lilac and fuchsia — clothes more often associated with well-behaved homemakers as opposed to policymakers. Nina Hyde of The Washington Post called them “pretty and neat, comfortable and appropriate and always American made.”

They looked modest, in every sense of the word, which was also the ethos of the Carter administration.

The Carters were, of course, replaced by the Reagans, whose approach to executive office showmanship was pretty much the opposite of “modest.” Mrs. Carter’s just-folks style of dress was relegated to the status of cautionary tale in the political playbook. Conventional wisdom had it that the American people simply didn’t want their first hostess to look quite so much like them after all — at least not once she (or her husband) had been elected.

Yet just as history has become kinder to the Carter administration, and Mr. Carter himself has become something of a model of an ex-president, it is also true that Mrs. Carter’s style as first lady suddenly looks unexpectedly relevant. After all, Jill Biden, the current resident of the East Wing, is also known for her folksiness, fondness for shirtwaists, lack of interest in telegraphing her fashion choices, and penchant for appearing in the same thing twice. Or three times.

In fact, she is celebrated for it, though the watching world no longer calls it wearing old clothes. They call it sustainability. And Rosalynn Carter did it — yes — first.