Henry T. Bishop (1853-1917) and three sons, James E. (1860-), Theodore (1852-) and William N.(1849-) were all photographers working mainly in Philadelphia, Altoona and Chambersburg, PA, and Minneapolis, Minnesota. Studios were named Bishop, H. T. Bishop, and Bishop Bros.
It appears there were as many as five other photographers named Bishop around the turn of the 19th century. Only one, Isaac R. Bishop actually worked in the Philadelphia area. Others were in Connecticut, Wisconsin and Massachusetts.
Not the one you were looking for? Here's the photographer's INDEX by name. Listed here are all the Cabinet Card photographers of the 19th century found in LOST GALLERY. This is a work in progress. For a look at the original postings go to LOST GALLERY.