Born in Detroit to a family of German immigrants, Sommer first studied drawing at the age of 11 with Julius Gari Melchers. Pursuing a career in commercial lithography, Sommer apprenticed at Calvert Lithography in Detroit, 1881–88, and subsequently worked at various lithography shops in Boston, New York, and England. In 1890 he went abroad for a year of study at the Kunstakademie in Munich. In 1891 he returned to New York and spent the next 16 years working as a commercial lithographer. In 1907 he moved to Cleveland to work for the Otis Lithograph Company, where he became friendly with William Zorach. Around 1910, and under the influence of Abel Warshawsky, Sommer began to experiment with impressionist colors; subsequently he experimented with a fauvist palette. He exhibited with the Cleveland “secessionists” at the Rorimer-Brooks Studios in early 1911 and cofounded the Kokoon Klub that summer. Around 1914 he moved to Brandywine, a rural valley about 20 miles south of Cleveland, where he converted an abandoned schoolhouse into a studio that became an important meeting place for modern artists, poets, and musicians. In May 1918 Sommer designed stage sets and programs for a production of Everyman by the Cleveland Play House. He exhibited in the annual May Shows at the Cleveland Museum of Art (1922–50). In the 1930s and 1940s he exhibited on a regular basis in Cleveland, Chicago, and New York. During the Depression he was employed by various New Deal art programs to paint murals for Cleveland Public Hall (1933), Cleveland Public Library (1934), the post office in Geneva, Ohio (1938), and the Akron Board of Education (1941). After the death of his wife in 1945, he was struck by chronic bouts of depression and alcoholism. Sommer died in Brandywine.
"Transformations in Cleveland Art" (CMA, 1996), p. 238