Thanks so much for the dating of the photo and the information about the photographer. I do have access to the original photo, but it is in England and I won't be able to take a photo of the back until later this autumn. I'll do that, however, and resubmit for further help in dating.
Henry Ingham, the subject of the photo was born in 1822. Does that help in the dating? He died in 1891.
Thanks,
Louise