The Freedmen and Southern Society Project, sponsored by the University of Maryland and by grants from the National Historical Publications and Records Commission and the National Endowment for the Humanities. Includes a fantastic sampling of primary source documents.

The Freedmen's Bureau Online, an impressive assemblage of Bureau records, sorted by state and including records on marriage, freedmen's labor, and "murders and outrages."

The Library of Congress' American Memory Web site includes a section on Reconstruction with links to primary-source documents.

The University of North Carolina-Chapel Hill's Documenting the American South archive. Over 1,200 sources on various aspects of Southern history, with a subject index.