On April 13, 2022, the staff of Business Reference Services hosted a webinar covering strategies and resources business librarians at the Library of Congress use to research old companies. While the recorded webinar uses resources available at the Library, some of the resources are available through your local library or historical society, both of which have resources to help with this type of research. This recording also covers print and electronic sources, both free and subscription, as well as giving a few tips and tricks picked up over the years.
If you are looking for the text transcript one is available.
Also, the webinar presented on June 6, 2021 has been recorded and can be viewed.