Very little is known about J.R. Foster. Active as a photographer in the 1860s and 1870s in New Hampshire (according to a New Hampshire business directory), he may have followed local regiments to war in hopes of making salable views or portraits of soliders for an interested local audience. In several instances, soliders who had worked as photographers in civilian life set up shop temporarily in their camps. It is possible that Foster was a relative of photographer Henry C. Foster, who was based on Morris Island during the Civil War.
Merry A. Foresta American Photographs: The First Century (Washington, D.C.: National Museum of American Art with the Smithsonian Institution Press, 1996)