Unpublished Federal documents are acquired, organized, and stored by the National Archives and Records Administration (NARA). The NARA, as the name suggests, is an archive, and organizes documents, like other archives, by provenance. In the case of the NARA, provenance generally means originating agency.
Published Federal documents are distributed to libraries through the Federal Depository Library Program, and can be identified using the Monthly Catalog of United States Government Publications and also through library catalogs.
For more help finding government documents, contact Research Information Services.
Below are digital collections of both published and unpublished documents: