If you are having trouble getting a handle on when some old photographs were made and they are the ones that bare an ID of an Ohio professional photographer on the back, you might want to check out the book Ohio Photographers 1839-1900 by Dianne VanSkiver Gagel, or even buy a copy. It lists the dates and locations of professional photographers in Ohio and will give you a handle on the years that they would have been made. If you are like me, you have several with no names and nothing but the photographer and his place of business to identify them. Fun, isn't it? John