Hi Judi, well, the sleeve and the long bodice are typical of the frilly early 1870s, as is the chignon high on the head. The lady is wearing a bustle which went out of fashion in about 1875, so I'd place this photo between about 1872 and 1875.
But the back bothers me...it isn't typical.
I'd really like to see the whole card please Judi, uncropped. I need to see the corners, very important. Can do?
Cheers,
China