Our Special Collections, located on the 3rd floor of John T. Richardson includes holdings related to Irish Literature & Drama. The list is available through the Irish Literature & Drama Bibliography and the Irish Studies Bibliography. Information about using Special Collections is provided on their website (linked above).
Historical newspapers can provide first hand accounts of events that an author may allude to in his/her work. In addition, you will find reviews of works that will provide you with insight to the public reception of the work at that time.
You can search Google Books or HathiTrust to find published books online. If it was published before 1923, you have a good chance of finding the entire book online.
What are primary sources? Primary sources enable the researcher to get as close as possible to what actually happened during an historical event or time period. Primary sources can be treaties, photographs, legislation, diaries, speeches, interviews, letters, manuscripts, newspaper articles, artifacts, or other materials. Depending on your field of study, a primary source might also be an original scientific experiment or anthropological fieldwork.
Primary sources are not books or journal articles that provide secondary analysis, or describe something that happened somewhere else.
Primary sources can be in any format. Primary sources might be original documents in archives, republished in a contemporary book, available online, or preserved on microfilm. The content of the material -- rather than the format -- determines whether or not it's a primary source.