In the late 1960s, Romaine Brooks gave a sizable cache of paintings and drawings to the Smithsonian American Art Museum. Brooks was then in her 90s, and her reputation was in serious decline. Brooks, it seems, had skipped most of the innovative currents of 20th-century art, and had more in common with 19th-century figures such as James McNeill Whistler than the titans of cubism or fauvism or futurism or any other of the major “isms” practiced during her lifetime.

The American Art Museum is putting much of that gift on display in the exhibition, “The Art of Romaine Brooks,” which includes 18 paintings and 32 of her wonderfully concentrated drawings. The rediscovery of Brooks in recent decades was driven, in part, by a new scholarly focus on gender and sexuality, and greater interest in and tolerance for artists who worked within gay or lesbian milieus. Brooks’s 1923 self-portrait, for example, was one of the more arresting works at the National Portrait Gallery’s exhibition of gay themes in portraiture, the 2010 “Hide/Seek” show, which was censored by the previous Smithsonian secretary, Wayne Clough.

It’s good to see Brooks’s work not as part of a larger theme, but in the context of her own career and development as an artist. Brooks was born in 1874, had an unhappy childhood, fled to Paris when she came of age and, in 1902, inherited enough money to live independently, both as an artist and as a lesbian. The earliest work on view, the 1904 “Charwoman,” prefigures tendencies in her later work toward relatively flat surfaces and a severe but elegant economy of color. The woman’s face isn’t pretty, and her harsh features are exaggerated by sickly white highlights—a strange quirk that one doesn’t see in works made only a few years later. The working-class figure looks to her left, at boats in a river, perhaps a reference to Whistler’s interest in the docks and marine traffic along the Thames.

A decade later, Brooks had mostly consolidated her technical and stylistic language. In 1910, she still produced some rather awkward contour lines in works such as “White Azaleas,” a curious, horizontal nude that may recall Manet's “Olympia,” yet positions its subject more discretely and dwarfs her on an enormous sofa. In other paintings made the same year, and especially those made a few years later, the contour line goes from liability to distinctive stylistic marker, emerging as an essential feature of work that celebrated flat planes and a figures who confront the viewer almost like actors bathed in a spotlight against a gray theatrical backdrop.

Romaine Brooks, Self-Portrait, 1923. (Courtesy of the Smithsonian American Art Museum, Gift of the artist)

Most of Brooks’s subjects were women, and many were lesbians. Some wear men’s clothes, have short-cropped hair and project an appealing androgyny. One of the most famous, a portrait of the British painter Hannah Gluckstein (who went by the name Peyter Gluck), looks to be the sort of winsome English lad who sits in the garden reading Rupert Brooke while listening to Wagner on the Victrola. He’s handsome, and the painting’s title, which prefigures the ironic post-modern games with titles in fashion today, identifies him as “Peter (A Young English Girl).”

It’s tempting to read that as merely a coy illusion to the subject’s self-presentation as lesbian via masculine attire. But it also hints at deeper questions and ideas about gender. Imagine, for a moment, that this isn’t a portrait of a woman who calls herself Peter and dresses in men’s clothing, but rather that it is a picture of a boy named Peter who is also “a young English girl.” That mental exercise leads one away from binary gender categories, and gets at the far more interesting, and largely unexplored, territory of gender and sexuality beyond the either/or world of normative heterosexuality.

It also leads one to wonder whether some of Brooks’s portraits are, in fact, portraits at all. Certainly they depicted recognizable people. But by using recognizable people, Brooks could explore gender in far more daring ways. If “Peter” the hermaphrodite, or transgender boy/girl, or indefinably queer figure unsettled anyone, Brooks could always say: “No, that’s just a portrait of Hannah Gluckstein.” A 1920 painting of Renata Borgatti, a pianist, sitting at her instrument also pushes androgyny to the point that one wonders whether that, in fact, is the subject of the painting, not the pianist. And the piano itself, with its black and white keys, its sonic illusionism of singing, and its 19th-century association with heroic male virtuosos with matinee-idol good looks, might be part of the larger game of erasing sexual distinctions.

The paintings are striking, but the drawings are no less interesting. Some were produced in parallel with her unpublished memoir, “No Pleasant Memories” and are best understood not as illustrations for that grim text, but as elaborations or extensions of the emotions and ideas driving it. Brooks’s drawings, which flirt with the surreal, may remind one of those of artist, novelist and filmmaker Jean Cocteau, with whom she had a fraught and ultimately broken friendship, although even friendship might be too strong a word. They often look as if drawn in one confident and continuous line, without lifting the pencil, so that figures are fused into one another, with some lines doing double or triple duty.

The drawings were made mainly in the early 1930s and are more private documents than the paintings. They were likely to have been part of the ongoing psychic struggles Brooks endured as she wrestled with memories of an abusive mother. Brooks moved from Paris to Italy in 1937, and after World War II she basically gave up on art and increasingly kept to herself. But a 1967 interview, rediscovered in the Smithsonian Archives of American Art and translated in 2014, reveals a woman who might not be able to remember every name or date but who was still sharp and charming.

In the interview, Brooks recalled studying art in Rome and being the only woman in a drawing class. Male students harassed her, and one took to leaving pornography where she was working.

“Finally, one morning, I was tired or something and I saw these books, and I took my paint box and I smacked him over the head,” she said. It sounds like a comic anecdote, except it ultimately led to her leaving the school out of fear of violent reprisals. If anyone is ever foolish enough to ask you, “Why are there so few great women artists?” have that anecdote ready. Together with the works on view in this exhibition, the silly question answers itself.

The Art of Romaine Brooks is on view at the Smithsonian American Art Museum through Oct. 2. For information, visit americanart.si.edu.