Expand your research by checking out the Pennsylvania Online Historical Newspapers here.
Links to directories at GenealogyToday are to the search engine for that particular directory, which is searchable without a subscription. Non-subscribers can use the search engine and see a listing of possible results (but no images or further details). For more information on how to access subscription websites, read Number 5 on my FAQs page.
The Historic Pittsburgh City Directory Collection can be searched across all its directories here.
The LancasterHistory City Directory Collection can be searched across all its directories here (select the appropriate year range from the menu at the bottom of the search page).
York City Directory, Gopsill, 1863-4 - Free (LancasterHistory)
- includes Harrisburg, Lancaster, and Lebanon
Windsor Borough Directory, Smith, 1932 - $ (GenealogyToday)