Was that old photograph taken in Chicago?

If it was professionally done, you may be able to date it using the Chicago History Museum's nifty tool, Chicago Photographers, 1847 through 1900, as Listed in Chicago City Directories (Chicago: Chicago Historical Society Print Department, 1958). The roughly 80-page typescript runs from Abbey to Zolk, includes ambrotypists and daguerrotypists, and is now on line in your choice of formats at the American Libraries part of the Internet Archive. (For some fun, search on your favorite research counties from their home page.)

Note: these listings, reasonably enough, were taken from the classified business sections of the annual directories. If you have a photo with a name not contained in this book, bear in mind that not every individual listed with a given occupation or business showed up in the classifieds. Search for them yourself, either at the CHM or the Newberry in person, or on line (Footnote.com has by far the best coverage, although its presentation is sometimes lacking).

Hat tip to the always-concise Newberry Library genealogy news blog.