During his youth in New York State and Vermont, Warner showed an interest in carving, and exhibited some of his earliest works, in chalk and plaster, at various county fairs. He was unable to pursue sculpting professionally, however, until 1869, when he had finally saved enough money to go to Europe to study. He was admitted to the Ecole des Beaux Arts in Paris, studied with Francois Jouffroy, Jean FalguiŠre and Michel Mercier, and apprenticed himself to Jean Baptist Carpeaux. On his return to the United States in 1872, he established a studio in New York, but was at first discouraged by the lack of commissions. The first exhibition of one of his works, an ideal piece, in an Academy annual in 1873 does not seem to have helped. The patronage of Daniel Cottier among others, brought an end to this period of stuggle in about 1876 when Warner began to receive a number of portrait commissions. His busts of Julian Alden Weir and Charles DeKay both date from 1880 (both, Century Association, New York). In 1877, Warner participated with other young painters and sculptors in the founding of the Society of American Artists, and his work appeared in the annual exhibitions of that organization for many years. His participation in this rebellious organization, however, did not prevent him from exhibiting at the Academy; in only five of the years betweem 1873 and 1891 did he fail to be represented. In 1888, he was engaged by the Academy to teach sculptural modeling in its school. By the end of the year, however, it was noted that no students were availing themselves of the opportunity to study sculpture and the subject was dropped from the curriculum. In 1893 the Academy decided student interest was sufficient to warrant another try, and Warner again joined the faculty. He had finished only his third year of teaching at the Academy at the time of his death.
Besides portraits, Warner also designed several well-known ideal or allegorical pieces. Possibly the most famous of these is his Diana (Metropolitan Museum of Art, New York) which had the distinction of being chosen to illustrate the jacket of Lorado Taft's seminal History of American Sculpture, published in 1903. In 1888, Warner was commissioned by Stephen Skidmore to design a bronze and granite public fountain with caryatids for Portland, Oregon. Between 1889 and 1891, he visited the Pacific Northwest and modelled portrait medallions of American Indians representing various tribes of the region. These included Chief Joseph of the Nez Perce (Metropolitan Museum of Art) which was shown at the Academy in 1890.
At his early death as the result of a bicycle accident, Warner was working on a commission for two huge bronze doors for the Library of Congress, a project later finished by Herbert Adams. He had just completed his second one-year term on the Academy Council at the time of his death, and his colleagues entered the following tribute to him in minutes:
It is hard to become reconciled to the untimely death of Olin L. Warner N.A. who had endeared himself to us all by his great talents, his sturdy integrity, his conscientious performance of duty. As a member of the Council he was rarely absent, and his sound judgment, directly and fearlessly expressed, was of great value in our deliberations. . . . - to be so cut off almost at the beginning of the real work of his life, is a serious misfortune to American Art.
