The databases listed below have been included for those that are primarily doing research that is more current. Additional resources for those doing deep historical research can be found at the bottom of the page.
The subscription resources marked with a padlock are available to researchers on-site at the Library of Congress. If you are unable to visit the Library, you may be able to access these resources through your local public or academic library.
The databases above can be used for historical research but those listed below are intended for those that are specifically doing deep historical research. There are others that may be of interest, but these are a good starting point.