The full text of Angelina Grimké Weld's antislavery speech at Pennsylvania Hall is available through PBS online:
Several more primary-source documents pertaining to slavery and abolition are also available online through the PBS Africans in America series:
"I will be heard!" is an excellent collection of documents and descriptions from the Cornell University Division of Rare and Manuscript Collections:
The full text of the Court opinions and the arguments in the Amistad case are available from University of Missouri-Kansas City School of Law:
The Sojourner Truth Institute in Battle Creek, Michigan, which is doubtless celebrating the 210th anniversary of her birth (in 2007):
Sojourner Truth's Narrative is also available on-line:
The Frederick Douglass papers at the Library of Congress, searchable by keyword:
Some links to primary sources on Lucretia Mott and the women's rights movement:
The Avalon Project at Yale Law School: Documents from pre 18th century to the present. Contains several primary-source documents, on slavery, antislavery movements and legislation: