A Philadelphia painter, Fenimore died in his early thirties of typhoid fever, right at the time that he was gaining recognition as a prominent landscape painter. His obituary in the Philadelphia Inquirer noted, “some pictures lately painted by him show that he was beginning to attain a mastery.” He exhibited at the Pennsylvania Academy of the Fine Arts from 1861 to 1869, and painted in New England, including the Saco River Valley and Mount Washington, in the mid-1860s.