The story of the women’s movement during the Trump era cannot be told without clothing: There was the knitted pussy hat, the white suffragist suit, the “Future Is Female” T-shirt and the Lingua Franca sweater, all of which now fall somewhere between important cultural artifact and mockable meme, depending on who you’re talking to.

That era may have ended, but setbacks to feminist causes haven’t — and neither has the market for making political statements via merchandise. One rising example: shirts, sweaters and hats printed with the year 1973, when the Supreme Court ruled on Roe v. Wade, establishing the constitutional right to abortion. That’s it — no bold slogan, just a four-digit number.

Last Monday, after the leak of a Supreme Court draft opinion that would overrule Roe v. Wade, protesters in Washington descended on the court. Demonstrations in other major American cities followed; the next evening, more than a thousand people gathered in Foley Square in Manhattan.

They were encouraged to wear green, a signature color of the abortion rights movement. But 1973 gear was also present, including a cream sweater worn by Lizz Winstead, a speaker at the protest. She is the founder of the nonprofit Abortion Access Front and one of the creators of “The Daily Show.”

Then, over the weekend, the actor Benedict Cumberbatch and at least six cast members of “Saturday Night Live” closed the show wearing matching white 1973 tees. Arcade Fire’s Win Butler, also performing on the show that night, had taped the year onto his guitar.

Sales of 1973 products have spiked in the 10 days since news of the draft opinion, according to Social Goods, an online boutique for activist apparel. Social Goods, which donates a portion of 1973 sales to the National Institute of Reproductive Health ($5 from every $45 T-shirt, for example), declined to provide sales figures, but said its site traffic was up more than 300 percent from the previous week.

Yet while the design may be having a moment, it isn’t quite new. This particular 1973 shirt was first designed in 2013 by Pamela Bell, on the occasion of Roe’s 40th anniversary, she said. Even then, “there was a lot of talk about the impending potential of it being overturned,” said Ms. Bell, who also used a font from the 1970s in the design.

Ms. Bell is the founder of Prinkshop, which creates products (like silk screen T-shirts) for advocacy campaigns. She was also one of the four founding partners of Kate Spade and Jack Spade, and said the project was in part inspired by advice from another founding partner, Andy Spade.

“He once said to me: ‘There are two kinds of advertising. You can say “Libby’s Libby’s Libby’s” on the label,’” referring to the commercials from the ’70s that repeated the brand’s name over and over and over. “‘Or you could do something that’s more thought-provoking and kind of subtle.’”

Over the years, interest in 1973 shirts has been “slow and steady,” said Ms. Bell, who would sell the gear at events like Tina Brown’s Women in the World conference. But each new crisis in the abortion rights movement would bring a jump in sales. (Celebrities like Amy Schumer and Busy Philipps already wore 1973 goods before the latest Roe news.)

On Social Goods, which is the exclusive retailer of the Prinkshop designs, 1973 sales began steadily climbing last fall, when Texas banned most abortions. With focus back on the Supreme Court, there has also been some renewed interest in Ruth Bader Ginsburg merch, despite the hint of backlash to the justice’s feminist icon status that came after her death. Lisa Sokolov, who founded Social Goods with her sister Kate, said recently that an “RBG” notepad and gavel gift set sold out on the site, along with some cards and pins.

The 1973 design is still relatively unknown, though it has spawned similar versions on sites like Zazzle and Etsy. It can have the same clandestine effect as a secret code; when wearing it, Ms. Bell said, “someone will give a thumbs up or a smile, because they know what it is. Or someone will say, ‘Is that the year you were born?’”

There is something restrained about it, too; less controversial or optimistic than pussy hats or “The Future Is Female” shirts, which were both accused of being exclusionary, and were eventually ridiculed. It’s also less confrontational than another Prinkshop tee supporting abortion access currently sold on Social Goods, which reads: “You are not the boss of V.” (The “V” serves as a kind of downward arrow.)

But Kate Sokolov defended the more subtle approach: “When you say what it is and why you’re wearing it, it packs a huge punch,” she said. “It starts conversations.”