A distant cousin of the landscape painter Benjamin Champney, James Wells Champney was reared by aunts after his mother's early death. He began studying drawing at the Lowell Institute, Boston, where he also attended anatomy classes taught by Oliver Wendell Holmes. In 1859 he took a job with the Boston wood-engraving firm of Bricher and Russell, staying until 1862, when he joined the Forty-fifth Massachusetts Volunteers, a Union Army unit that saw action in the Carolinas. Champney's war service was ended when he contracted malaria. He returned to Massachusetts and by 1864 was teaching at the "Young Ladies Seminary" of Dr. Dio Lewis in Lexington.
Champney left for Europe in October 1866. After a month in London, he settled in Paris, studying informally in the galleries of the Louvre. During the summer season, Champney worked under Edouard Frère in Ecouen. He also spent time in 1868 at the Académie Royale in Antwerp and was in Rome from 1869 until his return to Boston in 1870. He stayed in Boston briefly, returning to Paris in time to witness the events of the Commune, before going on to Germany. By 1872 he was once again in the United States, lecturing and doing illustration work. In 1873 Scribner's Magazine asked him to accompany Edward King on a long tour of the South and Midwest. His drawings illustrated King's series of articles on Reconstruction, which were compiled in a book, The Great South (1875). For this project Champney traveled some twenty thousand miles and made more than five hundred sketches. In Kansas he reencountered a former pupil from Dr. Lewis's seminary, Elizabeth Williams, with whom he eloped.
The couple traveled to Europe in 1874, where their son, Edward Frere [sp. ok!] Champney, was born. A commission from the periodical L'Illustration to illustrate scenes of American life brought them home in 1875, and soon after, they moved into Elizabeth's ancestral home in Deerfield, Massachusetts. Champney became a professor of art at Smith College, Northampton, Massachusetts, in 1877, a post he retained until 1884.
Champney exhibited consistently at the National Academy of Design beginning in 1874, generally showing genre subjects. In 1879 he established a studio on Fourth Avenue, near the Academy building, and in the same year became a lecturer in anatomy at the Academy school; he repeated this role in the 1880-81, 1885-86, and 1887-88 school seasons. He also continued producing illustrations, accompanying Herbert Smith to Brazil in the summer of 1878 on another assignment from Scribner's.
In the early 1880s Champney's career changed considerably when he became a devoted exponent of the pastel medium. He began making copies, or "translations," in pastel of predominantly eighteenth-century European paintings. This work found ready buyers and received considerable attention in the press, especially following an important 1897 show at M. Knoedler and Company, New York. He also did pastel portraits of leading New York theater and society personalities. In this period Champney also turned to decorative work, executing murals for the Hotel Manhattan in 1898 and designing stained glass.
In his later years he developed a keen interest in photography, often lecturing on the subject. Following a meeting of the Camera Club, Champney attempted to jump from an elevator that was stuck between floors, fell to the bottom of the shaft, and died.