Slavery predates written history, and it continues into the present, but this category is about the system of slavery in 19th century America, which was a system wherein most of the slaves were black and were held by whites. Although slavery had been an issue, and a contentious one at that, since before the establishment of the United States, it hit its peak in the mid-19th century with the Dred Scott decision and the Fugitive Slave Act.
Regular Websites
American Slave Narratives: An Online Anthology
An online anthology of first-hand accounts of freed slaves, as compiled by the Works Progress Administration. The stories recount lives on plantations, small farms, and in cities. - American Slave Narratives: An Online Anthology
http://xroads.virginia.edu/~hyper/wpa/wpahome.html
History.com: Slavery in America
The History Channel shares articles about the foundations of slavery in America, the rise of the abolition movement, and the emancipation of the slaves as well as the legacy of the institution. - History.com: Slavery in America
http://www.history.com/topics/slavery
Slavery and the Making of America
Displays a timeline of slavery in the United States from 1619 to 1874 as well as fist-hand accounts by ex-slaves as recorded by the WPA and further resources. - Slavery and the Making of America
http://www.pbs.org/wnet/slavery/
Contains articles about slavery in various places within the United States, Bantu place names in South Carolina, and a historical overview of the practice. - Slavery in America: History
http://www.slaveryinamerica.org/history/overview.htm
Slavery: The Peculiar Institution
Delves into the Atlantic slave trade, strategies for abolition, the attempted mutiny of the Brigantine Hope, and the successful mutiny of the Amistad. - Slavery: The Peculiar Institution
http://lcweb2.loc.gov/ammem/aaohtml/exhibit/aopart1.html