Institute of Historical Research
Internet History Sourcebooks Project
A collection of primary source documents from ancient to modern times, for example: Modern History
National Archives (UK) - Education
The Cabinet Papers (from the National Archives) including:
CAIN: Conflict Archive on the Internet
Guide to information on the Northern Ireland Conflict and Peace Process, including many bibliographies, collections of documents, and databases.
Use quotes to locate a specific phrase, e.g. "Irish Civil War".
Limit your searches to a specific high level domain such as .edu, .org, .gov, and more, you can use the site: command to accomplish this. An easier way to do this is use Google Advanced Search and then enter preferred doman in the site or domain box.
For example, you only want to search U.S. academic educational sites for something. Limit our search results by typing site:.edu or type .edu in the search box.
Check Purdue OWL's guide on Searching Online.