OneSearch is a "discovery service" from EBSCO that allows you to search most of the library's resources in "one search"! Hint: You will get a lot of results, so use the limits on the left side to focus in on what you need. (EBSCO)
Search the full-text of millions of books. Use it as a "discovery" tool to find books on your topic. Books in the public domain (generally, pre-1923) are available full-text. Newer books offer limited viewing, ranging from quite a few pages to nothing.Note: This is just for books (and some magazines). To include scholarly articles in your search, use Google Scholar.
The Atlas provides over 60 socioeconomic indicators down to the county level, including demographic, economic, and agricultural information. In addition to the visual maps, you can download data in spreadsheet format.
Organized into 17 categories, such as administrative boundaries, agriculture, atmosphere, biology, business, etc. Data is fully cataloged and searchable by key word, date, content, data category or geographically. - Guide to Reference
"The National Historical Geographic Information System (NHGIS) provides, free of charge, aggregate census data and GIS-compatible boundary files for the United States between 1790 and 2000."—Project information