Eight female mannequins stand in an exhibition room of the Jewish Museum Milwaukee here, clad in smart and urbane apparel, the sort that might have come from a “Thin Man” film, or something with Ginger Rogers and Fred Astaire. The clothing went on display about two weeks ago. The fashions are both text and textile, a story of life and death told in fabric, and a recollection during the High Holy Days of mortality and persecution.

The story began decades ago with a family divided between two continents and two destinies. For the purposes of the exhibition, “Stitching History From the Holocaust,” it also started on the day in 1997 when a lawyer named Burton Strnad introduced himself to Kathie Bernstein, an archivist collecting photographs and artifacts from Milwaukee’s Jewish community.

Mr. Strnad (pronounced STRAH-nod) had moved his mother into an assisted-living facility and was cleaning out the house. In the basement, he found several items that he thought might interest Ms. Bernstein. One was a letter, dated Dec. 11, 1939, and cleared by Nazi censors in Czechoslovakia, and another was a packet of dress designs.

The letter had been written by Paul Strnad in Prague to his cousin in Milwaukee, Alvin Strnad, Burton’s father. In careful language, crafted to slip through the censor, Paul asked Alvin for help getting him and his wife sponsorship to immigrate to America, which would mean escaping from Czechoslovakia’s German occupiers. Paul’s hope was that someone in Milwaukee would offer his wife a job as a dressmaker. The eight colored drawings in the packet — for an evening gown, two coats, two suits and several daytime dresses — were meant to support the appeal.

Ms. Bernstein recorded the donation and assured Burton Strnad, “We’ll use it one day.” As compelling as the material was, it left gaping questions. Paul Strnad’s letter had not mentioned his wife’s name, though he had included a snapshot of them both. Who were these people? What had happened to them?

Years passed, and Ms. Bernstein’s growing archive became the core of the Jewish Museum Milwaukee, which opened in 2008. “We had a concept of what we wanted our Holocaust area to be,” said Ellie Gettinger, the museum’s education director. “We wanted to make it very local and very personal, because we knew most of our visitors would not be Jewish.”

So the Strnad letter, photograph and clothing designs went into a display case in the museum’s permanent collection. Soon after, Ms. Gettinger’s mother came for a visit. “You could do more than that,” she told her daughter of the sketches. “You could make them.”

What sounded at first like maternal second-guessing wound up inspiring Ms. Gettinger to plunge into research. In the online database of Yad Vashem, the Holocaust museum in Jerusalem, she found a “page of testimony” identifying a Holocaust victim named Hedvika Strnad. The document, which had been submitted by a niece in the 1990s, stated that Hedvika was married to Paul Strnad and had worked as a “Lady Taylor.”

That confirmation provided enough incentive for the museum to develop an exhibition on Paul and Hedvika Strnad, as well as their American relatives. The challenge was to transform Hedvika’s drawings into three-dimensional reality.

In the fall of 2012, the Milwaukee Repertory Theater had done a production of “The Diary of Anne Frank,” giving a special performance at the Jewish museum. The show had required period costumes. So a year later, as work commenced on the Strnad exhibition, Ms. Bernstein and her staff turned to the theater’s costume artists.

Jessica Hartman Jaeger at the repertory theater assigned a dozen people from the costume shop to the task. Over nearly 3,000 hours spread across 10 months, they matched the colors in the drawings; determined the likely fabrics, like rayon and bouclé; extrapolated the sketches into patterns; and assembled the dresses and coats with matching hats and shoes.

To Ms. Jaeger, these looked like clothes meant for fun, similar to what a young woman might have worn for a day of shopping or a movie matinee. Yet all the spunk and verve they exuded stood in contrast to what had befallen the Strnads. Unable to get out of Czechoslovakia because of the United States’ tight restrictions on immigrants and refugees, they were interned in the Theresienstadt concentration camp, deported to the Warsaw ghetto and killed without any record.

“I felt so inadequate,” Ms. Jaeger recalled. “You want to do justice to the designer. You want her vision to be realized. But you can’t talk to her about it. And the reason why is tragic.”

Even as the dresses were being made, another piece of history dropped into place. Ms. Gettinger had been searching for the niece who had filed the Yad Vashem form, Brigitte Neumann Rohaczek, and ultimately found her listed in a footnote to a German-language book about the Kindertransport, which had rescued Jewish children. She wrote to the author: No reply.

At about this point, in late 2013, a college student studying abroad in Germany, Tyler Grasee, contacted Ms. Gettinger asking for a summer internship. She put him to work trying to find Ms. Rohaczek. Within weeks, Mr. Grasee had her address and telephone number in Nuremberg.

Mr. Grasee then interviewed Ms. Rohaczek, and from her memory poured palpable details of Hedvika. She liked to be called Hedy; she had red hair; she smoked; she owned a dressmaking shop. Sometimes she had her seamstresses make clothes for Brigitte’s dolls. Ms. Rohaczek also gave the museum a letter from Paul to her father, with a handwritten note from Hedy at the bottom.

This summer, Burton’s adult daughter Karen came from Texas to meet with the museum’s staff. While in Milwaukee, Karen Strnad went through boxes and photo albums in her mother’s home. In one, she found the last piece of the exhibition’s mosaic: a letter from Paul to his cousin Alvin, dated October 1938, just after the Munich Agreement handed over parts of Czechoslovakia to Hitler.

“What a catastrophe has overtaken our country,” Paul wrote, “a catastrophe which has upset our whole life.”

When “Stitching History From the Holocaust” opened, 17 members of the Strnad family, some of whom had never met, attended. Last summer, Karen Strnad and Ms. Rohaczek traveled to the village where Paul Strnad was born. And on every dress and coat in the exhibition is a small, posthumous design label, with “Hedy” sewn in script modeled on her handwriting.

“There’s this Hebrew word, ‘hineni,’ that means, ‘I am here,’ and I’ve been thinking about it a lot,” Karen Strnad said. “Now I can say ‘hineni’ and be looking at a family member I’ve never known about before. I can say ‘hineni’ about Hedy’s creations. These dresses are artifacts of the history of my family. They are keeping them spiritually alive.”