Credo Reference is an online collection of encyclopedias, dictionaries, and other ready-reference books.
Letters and Papers
Researchers often find important information in the letters and papers of abolitionists. Black Boston activist William Cooper Nell's papers are particularly helpful, as are the Black Abolitionist Papers and the Letters of William Lloyd Garrison.
Includes primary sources from African Americans actively involved in the movement to end slavery in the United States (1830-1865). The UD Library also offers the online version.
The Frederick Douglass Papers by John W. Blassingame (Editor)