The postcard above, part of the Detroit Publishing Company’s “10000 series” is titled “The Rebuilding of Baltimore, Baltimore, Md.” The New York Public Library, somewhat unhelpfully, states that it was issued between 1898 and 1931.
My first thought, seeing a steel frame under construction just left of center, is that the title refers to the reconstruction of the downtown area after the February 1904 “Great Fire.” My second thought is that a lot of people – architects, real-estate investors, and just people interested in cities – referred to the construction of massive new fireproof buildings in downtowns starting in the 1890s as reconstruction of the cities. My third thought was that I don’t know Baltimore very well, so I can’t date the photo based on which buildings are visible. A similar photo of New York, I’d be able to date to within two or three years if I spent enough time on it.
You can address ambiguity by serious historical research, which I’ve done at times for research projects but obviously cannot do for blog posts. Or you can address historical ambiguity by saying “here are some possibilities and there may be others.” The second option requires being able to walk away from an open question, which can be exceedingly difficult.