The Freedom Archives

While not a graphic design archive, this repository contains a wealth of activist messages through graphic means. 

Here's how the Archive describes themselves:

The Freedom Archives is a non-profit educational archive located in Berkeley dedicated to the preservation and dissemination of historical audio, video, and print materials documenting progressive movements and culture from the 1960s to the 1990s. Offering a youth development program focused on engagement with these historical materials and providing media production training, we also produce original documentaries and educational resources for use by schools and organizations as tools for community building and social justice work.

The materials housed at the Freedom Archives—over 12,000 hours of audio and video recordings—include: weekly news, poetry, music programs; in-depth interviews and reports on social and cultural issues; numerous voices from behind prison walls and recordings of diverse demonstrations and activists. We are also in the process of scanning and cataloging thousands of historical documents, pamphlets, journals, newspapers, and other print materials from many radical organizations and movements which enrich our media holdings. The digitized materials in our archives are free for use and constitute a compelling record of 50 years of recorded sound, images and cultural diversity.  The collections are an invaluable resource for young people and students, teachers, diverse community organizations, filmmakers, activists, historians, artists, media outlets, and researchers.

Check out the rich archive of digitized global activist publications on the site here.