In addition to the excellent resources listed by Lana, here are a few that might also be useful:

"Women and Social Movements 1820-1940" is a database published by Alexander Street Press that contains primary source material. If you have access to it (it's available through some university libraries), it's an excellent source. Even if you don't have access through a university library, however, you can access some of the documents through this link:

http://womhist.binghamton.edu/search.htm

The Labadie Collection at the University of Michigan (a radical history special collection) has a number of primary sources on women in social movements in the United States. Online you can access some photographs as well as some links to documents and extensive finding aids.

http://www.lib.umich.edu/spec-coll/labadie

Also, the filmmaker Lizzie Borden explored questions of violence as a political strategy used by women in her film "Born in Flames."

If you are interested, here's an entry on Lizzie Borden in GLBTQ: An Encyclopedia of Gay, Lesbian, Bisexual, Transgender, and Queer Culture.

http://www.glbtq.com/arts/borden_l.html

And the University of Virginia's "Sixties Project" has some primary source material

http://www3.iath.virginia.edu/sixties/HTML_docs/Sixties.html