Many departments and agencies have catalogs for historical and current publications with links to online documents. Here are some.​

• Browse Government Accountability Office, and Search GAO reports and legal products
• National Library Service for the Blind and Physically Handicapped (NLS)
• Department of the Interior catalog
• National Park Service Library catalog
• National Transportation Library catalog
• Homeland Security Digital Library -  policy documents, presidential directives, and national strategy documents as well as specialized resources such as theses and research reports from various universities, organizations, local agencies and state agencies.

   

Science

• Lawrence Berkeley National Laboratory Library catalog
• BLM Library Catalog
• Bureau of Reclamation Library catalog
• Energy Efficiency and Renewable Energy Library catalog
• Environmental Protection Agency Library catalog
• Fermilab Library BOOKS Catalog - High-Energy Physics
• Los Alamos National Laboratory
• National Agricultural Library catalog
• National Library of Medicine catalog
• United States Geological Survey Library

Military

• Air Force Institute of Technology Library Catalog
• Air University Online Catalog
• Combined Arms Reserach Catalog - Command and General Staff College
• Defense Language Institute Library Catalog
• US Military Academy Library Catalog
• Marine Corps University Library Catalog
• Naval History and Heritage Library
• Naval Academy Library Catalog
• Naval War College Catalog

CyberCemetery – “permanent public access to the electronic web sites and publications of defunct US government agencies and commissions”

Memory Hole – 300+ rescued Congressional Research Service Reports that were pulled from the Web – fact-filled reports on current and hot issues

Wayback Machine – Internet archive – useful but is hit or miss