In her poems, Widdemer addresses the social problems of her day—such as child labor—and pays strict attention to traditional poetic forms. Her poetry collections include The Factories With Other Lyrics (1915); The Old Road to Paradise (1918), which shared that year’s Columbia University Prize (now known as the Pulitzer Prize) with Carl Sandburg’s Cornhuskers; and The Dark Cavalier (1958). Her work was featured in Harriet Monroe’s The New Poetry: An Anthology (1917), and Widdemer edited The Haunted Hour (1920). She also published more than 30 novels, including The Red Castle Women (1968), and the memoir Golden Friends I Had (1964).
Widdemer received several awards for her poetry, including the Lyric Prize, the Trimmed Lamp Prize, and the Literary Review Prize for Satire. She served as vice president of the Poetry Society of America and appeared on the radio series Do You Want to Write? A selection of her papers is held at the Syracuse University Library. Widdemer lived in New York City for much of her adult life; she died in 1978.