What was Georgia O'Keeffe's first major New York subject, painted in a series of skyscraper works?

Georgia O'Keeffe's first major New York subject in her skyscraper series was New York skyscrapers.

O'Keeffe began painting New York skyscrapers in the 1920s, including works such as Radiator Building—Night, New York. The buildings represented the modern city through strong verticals, geometric planes, and dramatic light rather than through detailed architectural documentation.

These paintings reflected the environment around her and Alfred Stieglitz, who lived in Manhattan. O'Keeffe's urban scenes sit alongside her flower paintings and later New Mexico landscapes, showing that her central concern was not one particular subject but the transformation of recognizable forms through composition and scale.

The answer is broader than a single landmark. Although she painted specific buildings, the skyscraper was the defining New York subject of this phase. Her city paintings are sometimes overshadowed by her flowers and desert scenes, but they were crucial to her reputation as an American modernist.