Historians of American libraries and librarianship might hesitate to consult the wisdom of former U.S. Secretary of Defense Donald Rumsfeld as a guide for conducting research. However, the aforementioned quote does provide a useful context for this essay because historical investigations must go beyond what we already know. Research has to delve into the past to recapture the "unknown unknowns" that await our curious probing of dusty documents and forgotten files and help us make better sense of all that has gone before and serves as prologue for the present. This examination seeks to identify, summarize, and emphasize, where appropriate, those writings that appeared during 2008 and 2009 to assist us all in better understanding our shared library past.