Here’s a new CRS report on GPO, complete with rich datasets (in document form) explaining GPO’s role as information distributor.
From its establishment in 1861, the Government Printing Office (GPO) has compiled, formatted,
printed, bound, and distributed documents that have recorded the activities of Congress (and the
work of other governmental entities). In current practice, more than half of all government
documents originate in digital form, and are distributed electronically. As a consequence of
electronic production and dissemination, some congressional materials are now more readily
available to wider congressional, governmental, and public audiences than when they were only
produced and distributed in paper form.