Some libraries have local search engines that permit researchers to look up their newspaper holdings.

From WESSWeb

Libraries with local search engines for newspaper holdings (generally on microfilm). You can look up the newspapers of interest to you and request them through interlibrary loan (please note that if you ask the microfom staff at the holding location for help, they may well refer you to interlibrary loan anyway).

Yale University Library Microform Reading Room search engine for US and foreign newspapers