Mediacloud
Open source platform for studying media ecosystems.

BYU News on the Web (NOW)
Investigate words, phrases and more from news

Chronicling America
Features historical American newspapers.

Internet Archive of eBooks
Contains primarily public documents.

GDELT Project
Open source resource which monitors the world's broadcast, print and web news.  

SEC Filings
To see examples of what you can do with SEC Filings, visit Rankandfiled

FCC Comments and Proceedings - example case study

Congressional Record

Government Publishing Office - download a variety of federal government documents including code of Federal Regulations, Congressional Bill Text and more. 

Congressional Hearings

Patents