In the winter of 1897, a New York City plumber taking a break from a job on Fifth Avenue did something that went viral (or at least the late nineteenth century equivalent). He walked into the Metropolitan Museum of Art to check out the exhibitions and was promptly asked to leave. The reason? His dirty overalls were deemed offensive to the sensibilities of this refined cultural space.

Initially reported in the New York Times, the incident made headlines across the country, sparking vigorous debate about the relationship between the museum and the working classes. According to the Met’s director, the plumber had been asked to leave because the odors emanating from his uniform might make other visitors uncomfortable. But many writers of the day sympathized with the dungaree’d ejectee. As one commentator, writing for the Butte Weekly Miner, pointed out, many of the objects in the museum were created by people who would be considered “homespun,” and of course the museum itself was built — and the exhibitions hung, and the building maintained — by workers. Americans have a long history of defining ourselves through our work, and the act of barring an honest laborer from a sanctified cultural institution struck many people as deeply un-American.

More than a century later, the spirit of this anonymous plumber has been vindicated by another museum — the Smithsonian National Portrait Gallery in Washington, DC. Through the exhibition The Sweat of Their Face: Portraying American Workers, and its hard-bound, full-color catalog, curators Dorothy Moss and David C. Ward aim to disentangle the complex — and often contradictory — attitudes toward labor in an American imagination seeded by Puritanism and founded on a racialized and gendered hierarchy that counts slavery among its original sins.

The title of the exhibition is from the Book of Genesis: after their expulsion from Eden, Adam and Eve were forced to labor for their own food. In his introductory essay, Ward points out that labor has often been seen as a way to redeem humanity’s inherently sinful nature — an idea that echoes both Max Weber’s The Protestant Ethic and the Spirit of Capitalism and a certain well-worn adage about idle hands. According to Ward, the virtue of labor as a form of self-determinism is exemplified in John Singleton Copley’s famous oil-on-canvas portrait of Paul Revere, whose patriotism is inextricably linked with his status as a skilled craftsman (Revere was a silversmith by trade).

Early American portrait painting has its roots in the bourgeois flattery of wealthy patrons, and given this history, Ward argues, it’s “impossible to create an authentic portrait of a member of the working or laboring class.” Portraiture developed as a way to valorize a form of elitism that is incompatible with the “denial of one’s individual selfhood” required of laborers. Ashcan School artists like John Sloan and Robert Henri tried to navigate the apparent paradox, says professor and historian John Fagg in a supplementary essay, by creating portraits that portrayed workers matter-of-factly, without elevating them or turning them into stereotypes. One such painting is Sloan’s Scrubwomen, Astor Library, an image that foregrounds a trio of humble, middle-aged women with brooms and sponges. As Fagg points out, Sloan’s scrubwomen are neither heroic nor stoic. Instead, they seem to have an “ambiguous relationship to their work,” which undermines any temptation to make them stand for anything other than themselves.

In early American oil painting, the presence of slaves typically signified the status or wealth of a slave owner. It wasn’t until the introduction of the camera that the self-serving myopia that prevented white Americans from seeing Black workers as fully human was penetrated enough for enslaved individuals to be portrayed as subjects in their own right. An anonymous ambrotype from 1860 shows an enslaved woman flanked by the two white children she was forced to care for. Although the woman in this portrait is objectified in every conceivable sense, her personhood is unmistakably present in the finely detailed exposure of her likeness onto glass. Here, in the early days of photography, we glimpse something of the medium’s power to capture a basic fact that had previously been invisible in the Euro-American tradition of fine art portraiture: This woman is not an object; she’s a human being.

Some eighty years later, Gordon Parks, the first Black staff photographer for Life magazine, created dozens of portraits of a woman named Ella Watson who worked as a custodian in a government building. In American Gothic, Parks’s most famous photograph of Watson, she is staged in front of an American flag holding a broom, in a pose intentionally reminiscent of Grant Wood’s painting of the same name. In other, more candid images, we see Watson at home with her daughter and grandchildren. Some of these photographs are just as poignant as Destitute Pea Pickers in California. Mother of Seven Children. Age 32 (better known as “Migrant Mother”), Dorothea Lange’s iconic portrait of Florence Owens Thompson — but they’re far less well known, for reasons that are best understood in terms of racism. Watson is Black; Thompson is a Cherokee woman who was widely assumed to be white during the first several decades of the photograph’s existence. (In her important essay about this image — not included in this volume — Sally Stein traces how Thompson became the “New Deal Madonna” in the eyes of many viewers.)

The burgeoning industrialization in the first half of the twentieth century gave rise to new, heroic paradigms for representing manual laborers, like Rosie the Riveter and the high-flying construction worker captured in Lewis Hine’s Icarus, Empire State Building. In the context of these historical archetypes, the faceless Latinx maids and gardeners depicted in Ramiro Gomez’s send-ups of paintings by David Hockney reveal a glaring double standard. White workers can be bold, fearless, and larger-than-life; non-white workers are almost always marginalized and interchangeable.

Nowhere does this trend feel more like a dog whistle than in Norman Rockwell’s Mine America’s Coal, a painting of a smiling coal miner created for a propaganda poster issued by the War Manpower Commission in 1944. Rockwell’s white, salt-of-the-earth patriot — the two stars on his lapel pin indicate that he has two sons in the war — is an image that still resonates in the contemporary American imagination. In his January 2018 State of the Union address, Trump expressed his desire to end “the war on beautiful clean coal.” There is, of course, no such thing as “clean coal”; Trump’s choice of language refers not to the reality of coal mining, but to the perceived purity of the white American workers whose livelihood — and thus their identity and illusion of self-reliance — has disappeared.

Though the printmaking processes of woodcut, etching, and lithography have had a hugely democratizing influence on the visual arts, the few prints in this exhibition and catalog are largely overshadowed by an emphasis on painting and photography. Elizabeth Catlett’s Sharecropper is a glorious exception; a portrait of an elder African American woman in a wide-brimmed hat, rendered in the strong graphic vernacular of linocut.

Born in Washington, DC, in 1915, Catlett was a descendant of slaves who encountered overwhelming racism and sexism when she tried to establish a career as an artist in the United States. In the 1940s, she moved to Mexico, where she was exposed to the struggles of indigenous Mexicans and became involved with the politically radical Taller de Gráfica Popular (TGP). Her labor-intensive portrait sings with the virtues of hard work and self-reliance, but in this case “self-reliance” is no mere illusion of identity. It’s a communal ethic; a way of seeing work neither as a penance nor as something heroic, but rather as the engagement of effort and resources toward a meaningful goal.

This story is absent from the exhibition catalog: Because of Catlett’s activism and association with the TGP — which included several card-carrying members of the Communist Party — she was barred from re-entering the United States for several decades, unable to return even to visit her mother on her deathbed. That this great American artist should be banished from her own country for simply questioning the core values of capitalism speaks volumes about the subtext of The Sweat of Their Face — an inescapable truth that undergirds all the works in this exhibition like an invisible armature.

For all America’s fetishization of “freedom,” the American worker has always been subservient to an all-consuming hierarchical system. Some of the subjects of these portraits are valorized, others merely humanized, but at no point does this exhibition catalog ask: who — or what — exactly are all these people working for?