Wetherill studied chemistry at the University of Pennsylvania (graduating in 1895) that provided him with the background for a sophisticated investigation of printmaking. He studied art at the Pennsylvania Academy of Fine Arts under Thomas Anshutz and Hugh Breckenridge (1894-1898). He then went to Paris where he studied at the Academie Julian under J.P. Laurens, and with J. M. Whistler. While there he painted the Parisian street scene and exhibited at the Salon Champs Elysee. He then went to the Isle au Moin for several years where he painted the Breton coast and peasant scenes.
Upon his return to Philadelphia he resumed studies at the Pennsylvania Academy where he took both day and evening life drawing classes (1906-08). He later settled in New York where he etched many city subjects including views of Wall Street, the East Side, and the bridges.
He won a medal at the Panama Pacific Exposition (1915) and a silver medal at the Sesqui-Centennial International Exhibition (1926) for "Pets" a full-length portrait of a woman in evening dress in a richly appointed interior with oriental accessories.
In 1928, five of his prints were included in the exposition de la Gravure Moderne Americaine at the Biblioteque Nationale, Paris; and in 1923 an exhibition of his sketches and etchings was held at the Arlington Galleries. In 1928 he helped found the Philadelphia Society of Etchers and served as its first president.
Memorial exhibitions were held at the Whistler House, Lowell, Mass (1929), which owns two paintings by him, "Girl in Brown" and "Freighters in Delaware River Fog"; at the Philadelphia Art Alliance (1932); and etchings at the Library of Congress (1935).
Wetherill was a member of the Brooklyn Society of Etchers, Allied Artists of America, and the Salmagundi Club.
Wetherill was a patriot and served his country well in World War I, dieing of wounds he served in that war.
