Julian Onderdonk captured the light and atmosphere of South Texas on canvas with an innate understanding of the land. Born in San Antonio in 1882, he was the first child of Emily Gould Onderdonk and artist Robert Jenkins Onderdonk. Julian was raised in a cultured environment and his education in the arts was fostered at an early age at the direction of his father.

At nineteen, with a loan from a generous neighbor, he traveled to New York to study at the Art Student's League as his father had before him. In the summer of 1901 he studied with William Merritt Chase at his Shinnecock School in Southhampton, Long Island. He continued to study with Chase through remainder of 1901, and 1902. Under Chase's tutelage, Julian's aptitude for painting en plein air was encouraged and given focus. He received instruction from Frank Vincent Dumond and later from Robert Henri as well, but it was Chase who had the most notable influence on his artistic development. The maturation of Julian Onderdonk's style can be seen most clearly in his paintings of Texas landscapes after his return to the state in 1909.

While in New York, Julian married Gertrude Shipman with whom he had two children. In 1906 he acquired the position previously held by his father, that of an art exhibition organizer for the Dallas State Fair. Three years later when he settled permanently in San Antonio, he continued to develop and apply en plein air techniques to his native landscapes. Among his favored subjects were early misty mornings, sunlit fields of bluebonnets, cactus in bloom, dusty roads and South Texas brush country. His position with the Dallas State Fair, which he held until his death in 1922, required frequent trips New York to organize works for the exhibition.

Julian Onderdonk enjoyed artistic recognition and popularity during his lifetime. His paintings have been exhibited in over 40 national and regional exhibitions.