[Discover] Search Newspaper Pages - Chronicling America (Library of Congress) http://www.loc.gov/chroniclingamerica/search_fulltext_advanced.html
(newspapers reference history research) 
[Discover] SRU: Search/Retrieval via URL -- SRU, CQL and ZeeRex (Standards, Library of Congress) http://www.loc.gov/standards/sru/ (xml search library phm)
[Discover] Today in History/LoC http://memory.loc.gov/ammem/today/today.html (history facts loc government)
[Discover] Working Group on the Future of Bibliographic Control (Library of Congress) http://www.loc.gov/bibliographic-future/ (cataloging library loc metadata)
[Discover] Library of Congress Experience (Library of Congress) http://www.loc.gov/experience/ (history loc library congress)
[Discover] SRU: Search/Retrieval via URL -- SRU, CQL and ZeeRex (Standards, Library of Congress) http://www.loc.gov/standards/sru/ (xml search library phm)
[Discover] Today in History/LoC http://memory.loc.gov/ammem/today/today.html (history facts loc government)
[Discover] Working Group on the Future of Bibliographic Control (Library of Congress) http://www.loc.gov/bibliographic-future/ (cataloging library loc metadata)
[Discover] Library of Congress Experience (Library of Congress) http://www.loc.gov/experience/ (history loc library congress)