Thomas J. Fenimore was 31 years of age when he died of typhoid fever on July 31, 1873 in Philadelphia, PA.  He was, therefore, born either in 1841 or 1842.  He began as a house painter but turned to fine art.  According the his death notice in the Philadelphia Inquirer of August 2, 1873, "some pictures lately painted by him show that he was beginning to attain a mastery (Inquirer, page2).

T. J. Fenimore exhibited at the Pennsylvania Academy of the Fine Arts from 1861 to 1869.  His White Mountain titles were Sunrise on the Saco (1866), Saco River (1867), and Mount Washington, N. H. (1869).  He exhibited Mount Chocorua at the Philadelphia Sketch Club in December, 1865.  He painted Cathedral Ledge in 1867.