Painter. His color abstractions number among the earliest American examples. Born in Philadelphia, he was a son of the important turn-of-the-century book and magazine illustrator A. B. Frost (1851–1928), who also painted popular outdoor sporting scenes. In 1890 the family moved to an estate near Morristown, New Jersey. Frost's formal artistic education began at the Pennsylvania Academy of the Fine Arts. In 1905 he went to New York to study with William Merritt Chase and Robert Henri. The following year, his family moved briefly to London before settling in Paris, where Frost studied at the Académie Julian and soon met Patrick Henry Bruce, who became a close friend. From 1908 they attended Matisse's class, and by 1912 both were working with French abstract color painters Robert and Sonia Delaunay. Frost returned permanently to New York early in 1915. Although not officially a synchromist, he pursued similar interests and was instrumental in spreading ideas about chromatic abstraction to Americans. As the synchromists had, Frost often used the figure (sometimes adapted from photographs) as the basis for color organization. He also produced completely nonobjective work even before his return to the United States. Tuberculosis took Frost's life four days before his thirtieth birthday. Almost none of his mature work survives, although some lost paintings are known in black-and-white photographs.