Google’s Ngram Viewer allows one to mine deep-level data. Digitization has benefits. William Bradford has been referred to as, and in fact was, a “photographic artist”. Ngram viewer provides a decade by decade look at how this term was used.
A possible first public reference to him as a “photographic artist” was made by Isaac Israel Hayes, in the 1874 Annual Report of the Journal of the American Geographical Society of New York.