A good place to start is with the Northwestern University Subject Librarians  and the Research Guides for specific departments and areas of study.

To see a list of the digital primary source databases available through NU Libraries, go to the  A-Z Databases page and limit the database type to "Digitized Primary Sources." Then filter by your subject of interest in the top left drop-down box.

Some examples:

Wiley Digital Archives

Gale Archives of Sexuality and Gender

Gale Archives of Political Extremism and Radicalism

The Sixties: Primary Documents and Personal Narratives 1960–1974 from Alexander Street

• Daily Northwestern archive: access via NUsearch with netID; if outside Northwestern, sign up for an Our Northwestern account

• Digitized Northwestern Publications

• Edward S. Curtis's The North American Indian

• Siege and Commune of Paris (available via Archive-it.org)

• William Hogarth and 18th-Century Print Culture

• Audio + Video repository houses the Libraries' archival and course reserve AV material, including the Wildcats Football Films and other digitized videos from Northwestern's history.

• Digital Collections contains the Libraries' digital image collections of primary sources from our distinctive collections. A Northwestern NetID may be required to access some material.

• Northwestern University Web Archive: documents and preserves Northwestern websites of unique and enduring value.

• HathiTrust is a collaborative repository containing digitized items within the public domain. Find Northwestern's Alumni Publication from 1903-1987 here.

Northwestern University Libraries Digital Collections