 Following that, he was employed for several years as an art critic for the (Washington) Evening Star.In 1900, he moved to New York and studied at the Art Students League with life drawing master George Bridgman and illustrator Walter Clark.His work was soon selected for inclusion in some of the country's most prestigious art competitions, at the Art Institute of Chicago, the Pennsylvania Academy of the Fine Arts, the National Academy of Design,

In 1903, with earnings from his painting sales, Warner traveled to Europe (he would visit there again four years later), where he studied in Paris at the Académie Julian, while also making sketching trips to Italy, Germany, Spain, the Netherlands, and other countries.