Help A Friend Find Key Dates in Library History

I’m passing along a request I read on my discussion board for Friends of the Library USA…John Gear writes to FOLUSA :

I’m with the Friends of Lansing Libraries (Lansing, MI).
We’re considering underwriting with our local NPR affiliate in return for acknowledgments. We can’t afford their regular rotation schedules, so I thought that maybe we could get some extra mileage out of fewer spots by placing them on key dates in library history, such as the day that Franklin’s library was founded in Philadelphia, etc. etc. etc.

Problem is, I’m having a hard time finding such a list. Does anyone have one or know of a good pointer to where I might find such a thing?

John Gear