With information on more than 113,000 immigrants from nearly 100 countries, this database will be a great resource for researchers whose family settled in Pennsylvania. Information compiled in this database was originally edited by P. William Filby and produced as a book volume called Philadelphia Naturalization Records. That book volume was compiled from an eleven-volume index originally completed by the Work Projects Administration (WPA) around 1940. That index is generally considered to be one of the most important documents in the American naturalization and immigration archive.

Listings Include:
- An individual's name
- Any alternate spellings or interpretations of that name
- The individual's country of former allegiance
- Date and location the individual filed a declaration of intention and/or oath of allegiance.