If you’re interested in searching historical newspapers from further afield (as well as American papers), take a look at elephind.com.
The portal makes it possible to search all of the world’s digital newspapers from one place and at one time. (Okay, not ALL but they’re working on it.) To date, these include newspaper collections from Australia’s and New Zealand’s national libraries, the Upper Hutt Newspaper Archive in NZ, and in the United States: Cambridge Public Library, MA, Chronicling America, the University of California, and the University of Richmond, VA. And it’s FREE.
Elephind was launched recently by the New Zealand-based company, Digital Library Consulting Ltd. The portal uses Veridian, the company’s own software, developed specifically for accessing digitized historical newspapers online.
Here’s a snapshot of the Advanced Search page. Click on it to visit to the page.