 Returning permanently to the US in 1909, he became affiliated with the Old Lyme Art Colony at Old Lyme, Connecticut, which (under the sponsorship of art patron Florence Griswold) had become a well-known center for American Impressionism.One of the leading participants in that colony was Childe Hassam, who was a close associate of Abbott H. Thayer, a painter who was widely known for his theories of natural camouflage.In 1915, at the Panama-Pacific International Exposition in San Francisco, Warner won a silver medal in the painting category, and a bronze medal in printmaking.