I've been looking at this photo for about an hour now...it has some mixed messages in it.
I think this is an 1860s photo.
The lady's skirt is pure 1860s, although I think it's being worn without the huge crinoline that went out of fashion in the late 1860s. The sleeving with its loose bell-shaped wrist was definitely the style in the 1860s, although as Jim points out it did remain popular throughout the 1870s.
The dress material is silk, which gave way to much heavier fabrics such as velvet and cottons in the 1870s, and this outfit shows no sign of the fringes and embellishments that are the hallmark of the 1870s.
The man's clothing, although I'm nnot very good at men's clothing, looks like1860s to me, and the square-toed boots are an 1860s thing, disappearing about 1870 or so.
Also the plain, full-length pose is very 1860s, and so is the plain backdrop of the photo.
But as Jim mentioned, the rounded corners of the card backing are problematic, as the rounded corners didn't come out, for the most part anyway, until the mid 1870s.
So...this is likely an 1870s reprint of an 1860s photo. It was common to have reprints made, particularly after someone had died.
The one thing this absolutely is not, is an 1880s photo.
So, mothball...how certain are you that this is a photo of Richard Devote and his wife?
It's a nice one anyway, and if you would like a nice restore you should scan it at 300 dpi, at least, because this is a very low-resolution scan and hard to make out detail in it.
Well...that's my take
Cheers,
China