I happen to collect stamps, specifically I specialize in revenue stamps used during and immediately after the U.S. Civil War (in order to pay for the war, Congress passed a tax on many financial transactions, paid via a stamp affixed to the document or merchandise).
Anyway, as I was perusing eBay for material, I came across a wonderful item that, not only was philatelic in nature, but appealed to my love of cats. It is the photograph shown below. I put in what I thought was a hefty snipe at $75, but was totally blown out of the water when it finished at $127.50 (by way of comparison, a normal non-specialty photo from that era is a $4-10 item).
It is a carte de visite (or "CDV" for short), a predecessor of the modern photograph, depicting a cat and her kittens. It would have been very unusual for someone to have gone to the expense of having a photography session just for a pet, but the inscription at the bottom of the CDV gives us a clue as to its origin:
By the name "Kitty Burnham" matching the name of the photographer, it is my conclusion that the photographer used his pets as subjects either in practicing or testing photographic methods or processes, or for use as promotional materials in his business.
By the revenue stamp being affixed to the back, we can narrow down the time period to somewhere between August 1, 1864 and August 1, 1866, which was the period during which photographs were taxed.