What type of artwork did Georgia O'Keeffe create in 1915 that established her abstract style?

Georgia O'Keeffe created a series of charcoal drawings in 1915 that established her abstract style.

These works reduced natural forms and ideas to lines, shapes, and tonal contrasts rather than depicting recognizable subjects. Their directness marked a decisive break from the academic approach she had learned in formal art training. O'Keeffe later described this period as an effort to express something that could not be conveyed through ordinary representational painting.

Her former classmate Anita Pollitzer showed some of the drawings to Alfred Stieglitz in 1916. Stieglitz exhibited them at his New York gallery, 291, making O'Keeffe one of the first American artists he promoted as part of the emerging modernist movement.

O'Keeffe did not remain exclusively abstract. She returned repeatedly to flowers, landscapes, bones, buildings, and other identifiable subjects, often treating them in highly simplified ways. The 1915 charcoal series is important because it established the visual language that underlay both her abstract and representational work.