Use Directories as a subject in either the main catalog or Worldcat. In the second box, search your city as a keyword. If there are too many results, limit the city to Subject. For worldcat, you'll need to go into the advanced search settings. Limit to books and ebooks for both the catalog and worldcat.
If you find a directory in Worldcat (ex "Middletown and Portland directory"), you can place an ILL and we'll try to fill it, BUT first, check to see if the title is scanned online in HathiTrust, Googlebook, or Internet archive.
In this case, Copies of the directory have been scanned by Internet Archive, FamilySearch, and open library.
Please note. In some cases, 19th century directories for smaller towns and cities may only exist on microfilm, but can still be found through WorldCat using the methods outline above. For those, place an ILL Request.