'The Girl in the Middle' reveals hidden history of Native American assimilation

Martha Sandweiss uncovers the forgotten life of Sophie Mousseau, a mixed-race girl caught between cultures during the 1868 Peace Commission.

Illustration Iryna Lupashchenko

By Anna Fadiah and Hayu Andini

When thinking about the long and painful history of Native Americans and their encounters with white settlers, the term “peace” rarely comes to mind. The Girl in the Middle, a new historical work by Martha Sandweiss, sheds light on one poignant moment amid centuries of conflict—one frozen in time by a photograph taken at Fort Laramie in 1868. This image, which centers on a young Native American girl surrounded by members of the U.S. Peace Commission, serves as the visual and symbolic starting point of a narrative that ultimately reveals the complex story of Sophie Mousseau, a child born of two worlds and trapped in the margins of American history.

Sandweiss, a professor emerita of history at Princeton University, uses The Girl in the Middle not just to explore this singular image, but to unravel the deeper story of Native American assimilation, the federal government’s failed promises, and the transformation of the American West following the Civil War.

A photo that captured a vanishing world

The titular image, a black-and-white photograph from 1868, shows six commissioners—some in military uniforms, others in civilian dress—gathered around a small, unnamed Native American girl wrapped in a blanket. While the men’s identities are scrawled underneath in pencil, the girl in the middle is anonymous. For Sandweiss, this erasure of identity becomes the guiding mystery of the book.

“Who is she?” she asks. “Why is she there?”

The answers unfold slowly. Early in the narrative, we learn her name: Sophie Mousseau. Born in 1860 to a French-Canadian trader and an Oglala Lakota woman named Yellow Woman, Sophie’s story is both deeply personal and broadly representative of the experiences of mixed-race families in the Plains. Yet Sandweiss withholds much of Sophie’s full life story until later chapters, instead drawing the reader into the wider context of the Peace Commission and the era in which the photo was taken.

The Peace Commission and its broken promises

Following decades of escalating conflict with Native American tribes, Congress in 1867 formed the Peace Commission with the aim of ending violence on the frontier. Its official purpose was to “remove the causes of war,” protect new rail lines, and devise a plan for assimilating Native Americans into white society.

This plan included coercing tribes onto reservations, ostensibly to protect their interests while paving the way for westward expansion. In 1868, the commission convened at Fort Laramie, a remote outpost in what is now Wyoming but was then the Dakota Territory.

Over 9,000 Native Americans gathered nearby. Tribal leaders agreed to cease attacks on settlers and trains and to accept life on designated reservations. In return, the U.S. government promised schools, food rations, and the closure of certain military forts. It was a peace built on unsteady ground.

Within a decade, those treaties unraveled. Most notably, the Black Hills—a sacred site ceded to the Lakota in perpetuity—were seized in 1877 after gold was discovered. The Girl in the Middle situates this betrayal as emblematic of a pattern that continues to affect Native communities today.

Two men, one image

Before returning to Sophie’s life, Sandweiss delves into the stories of two men closely connected to the Peace Commission: the photographer Alexander Gardner and Commissioner William Harney.

Gardner, a Scottish immigrant who arrived in the United States in the 1850s, had already made a name for himself during the Civil War. As an employee of famed photographer Mathew Brady, he captured haunting images of battlefield carnage and the faces of the Lincoln assassination conspirators. His Civil War work, Sandweiss writes, delivered “a blow to the gut.” After the war, Gardner turned his lens westward, documenting Native American life, railroad construction, and domestic scenes in and around Fort Laramie. His photos now serve as some of the most powerful visual records of tribal cultures under siege.

General William Harney, by contrast, represents the darker legacy of U.S. military involvement with Native tribes. Known to the Lakota as “Woman Killer” for his brutal attack on a Native village in 1855, Harney’s reputation for violence preceded him. Earlier, in 1834, he had whipped a young enslaved woman named Hannah to death. Despite this, he was appointed to the Peace Commission, embodying the hypocrisy of a government that professed peace while relying on men like Harney.

Sophie Mousseau, caught between two cultures

The most compelling sections of The Girl in the Middle are those that finally return to Sophie. She was fluent in English, French, and Lakota. She moved between the reservation and white settlements, bridging cultural divides that most could not navigate.

Her life reflects the complicated legacy of U.S. policy toward Native Americans. Her first husband, an Irish-born teamster, and her second, a mixed-race showman in a traveling medicine show, symbolize the shifting alliances and opportunities available to people of mixed heritage.

Sophie had 13 children, and her descendants pursued a variety of roles: interpreter, scout, rancher, farmer. One son, James Ryan, became a lawyer and may have been the first Native American to serve as a judge.

Through Sophie’s lineage, Sandweiss explores broader themes: the rise of entrepreneurial capitalism, the forced dispossession of Native peoples, and the evolution of race politics in the United States.

History preserved and lost

Sandweiss is a skillful writer who presents her research with narrative flair. Yet, at times, her book strays into tangents, occasionally overwhelming the reader with excessive detail. Still, the central story remains powerful, and her effort to reconstruct Sophie’s life from the margins of history is admirable.

The Girl in the Middle is ultimately a story of memory—how it is created, who controls it, and how easily it can be erased. The photograph that sparked Sandweiss’s quest preserved one moment, but without her work, Sophie’s name and story might have been lost forever.

By reclaiming that identity, The Girl in the Middle does more than solve a historical mystery. It restores dignity to a girl long anonymized by history and provides a lens through which we can better understand the fractured legacy of America’s expansion westward.

In the end, Sophie Mousseau’s life challenges us to reconsider what we think we know about assimilation, cultural survival, and the human cost of American progress. Through Sandweiss’s research and storytelling, the girl in the middle finally steps forward—not just as a figure in a faded photograph, but as a fully realized person whose life spanned cultures, eras, and generations.