The national women's history museum has an online exhibit up at http://www.nwhm.org/online-exhibits/africanamerican/index.html called Claiming Their Citizenship: African American Women From 1624-2009.

The interface is a little lacking, but some of the stories and information are interesting.  (Note that at the bottom of the page the "next" link sometimes goes to the next section of the exhibit but often leads to more pages on the current topic).

Also, I'm currently reading and loving Freedom in the Family, a mother/daughter memoir of the civil rights struggle by spec fic author Tananarive Due and her mother, Patricia Stephens Due.  I highly recommend it!