We’ll start this one with two of the most famous Victorian era photographers, Alexander Gardner and Mathew Brady. The Gardner blind stamp changes, but the only thing I can say for certain is that the stamp with the US Capitol building on it was during or shortly after the Civil War, as it touts his association with the Union army.
The Brady evolution is more obvious. The simple, plain version is his blind stamp from early in the Civil War period. The more ornate, shield-like design would be the 1870s, and the final version is the large letters.
Note the similar evolution in Chas Eisenmann’s blind stamp design. I don’t have a good idea of how long a span of time it took for his design to evolve – it may have been as little as a few years, or it may have been a decade or more separating them. I think though that once he changed it, he stuck with the globetrotter logo for an extended period, perhaps 20 years or more.
C.D. Fredricks bind stamp. I know I have another one of his that would be the “middle” design, but I haven’t hunted it down in the CDV album I have – it would be the “middle” in that it no longer says, “specialité”, but also lists Paris and Havana as studio locations, but the design is not as fancy as the late one.
M.P. Rice. Note the change also includes the addition of (most likely) his son to the masthead of the business. Using the date on the verso, this style had arrived by the late 1870s, so the shield designs would have been late 1860s to early 1870s.
Finally some others for which I don’t have early/late pairings. These are just a few of the others I have, but I like looking at them just for the art.