The Gerould Statistics.
This was my first data compilation. First edition was in 1984. This link is to the second revised edition in PDF format, 2010.
The Library Data Archive is hosted at the Library Research Service. It includes the two longitudinal databases of public library data which I originally recompiled at the U.S. National Commission on Libraries and Information Science and which I continue to maintain. Also included are publications of library by various US agencies. It is not a systematic collection but opportunistic: when I found something, I added it. It is the tip of an iceberg of data publications by the US government.
Possible birthday presents for moi