The Library subscribes to the full text of several historic newspapers online. These are a treasure trove of primary source material for various events.
If someone has already done research on a topic you are investigating you are encouraged to seek out the same sources. Sometimes you may find an abundant amount of material that wasn't important to them, but is perfect for you. Other times you may find you disagree with their interpretation, which will give you something to write about from a fresh perspective.
Theses and dissertations are a great place to find bibliographies (sometimes called literature reviews) Many can be found in this database-
The library has many databases dealing with historical topics. A full list of those database is available here
A subset of the above list contains those databases with large amounts of primary source material. That list is here
The databases listed below are some good starting points for your research-