This is the first publication devoted to Ida Ten Eyck O'Keeffe (1889-1961), the younger sister of Georgia O'Keeffe. It presents a thoughtful consideration of Ida's personal history and her creative work. As a professionally trained artist, graduating with an MFA from Columbia in 1932, Ida crafted an artistic identity that was dynamic and distinct in style and subject matter from that of her celebrated sibling. The positive critical attention she received became a source of tension between her and Georgia, who was determined that there would be only one painter in the family. Ida's complex relationship with Georgia and Alfred Stieglitz, though once loving and close, eventually devolved into estrangement. This volume illustrates works by Ida, including oils, watercolors, and monotypes, and examines their merits as well as their place within the aesthetics of American Modernism during the 1920s and 1930s.