"Solomon Northup, Kingsbury, Washington, New York". United States Census, 1830, National Archives Microfilm Publications. National Archives and Records Administration. 1969. p. 714. Retrieved March 29, 2014.
Northrup, Solomon (1968). Eakin, Sue & Logsdon, Joseph (eds.). Twelve Years a Slave. Baton Rouge: Louisiana State University Press. pp. 125–126. ISBN0-8071-0150-8.
Northrup, Solomon (1968). Eakin, Sue & Logsdon, Joseph (eds.). Twelve Years a Slave. Baton Rouge: Louisiana State University Press. pp. 211–212. ISBN0-8071-0150-8.
Northup & Wilson 1853, pp. 73–74, 270–273, 275, 292, 297–298. Northup, Solomon; Wilson, David (1853). Twelve Years a Slave. Auburn: Derby and Miller; Buffalo: Derby, Orton and Mulligan; London: Sampson Low, Son & Company.
J.C. Derby (1884), "William H. Seward", Fifty Years Among Authors, Books and Publishers, New York: G.W. Carleton & Co., pp. 62–63
Stampp, Kenneth M. (1956). The Peculiar Institution. New York: Vintage Books. pp. 60, 74–75, 90, 162, 183, 285, 287, 323, 336–337, 359, 365, 380. ISBN978-0-394-70253-7. Presence of "Twelve Years..." usually revealed by unindexed footnotes.
"John R. Smith letter" (1930s), Wilbur Henry Siebert collection, Houghton Library, Harvard University "Wilbur Henry Siebert Collection". Archived from the original on April 3, 2017. Retrieved January 9, 2014.
innercity.org
Genz, Michelle (March 7, 1999). "Solomon's Wisdom". Washington Post. Archived from the original on October 16, 2005. Retrieved February 19, 2012.
"Man sold into slavery never gave up on freedom". The Post-Star. February 23, 1992. p. 16. Retrieved June 26, 2021. Referenced Twelve Years a Slave by Sue Eakin and Joseph Logsdon, published by Louisiana State University Press.
Northup described the slave pen owned by William Williams in Washington: "It was like a farmer's barnyard in most respects, save it was so constructed that the outside world could never see the human cattle that were herded there. The building to which the yard was attached, was two stories high, fronting on one of the public streets of Washington. Its outside presented only the appearance of a quiet private residence. A stranger looking at it, would never have dreamed of its execrable uses. Strange as it may seem, within plain sight of this same house, looking down from its commanding height upon it, was the Capitol. The voices of patriotic representatives boasting of freedom and equality, and the rattling of the poor slave's chains, almost commingled. A slave pen within the very shadow of the Capitol! Such is a correct description as it was in 1841, of Williams' slave pen in Washington, in one of the cellars of which I found myself so unaccountably confined." "Free blacks kidnapped, sold into slavery in the shadow of the U.S. Capitol", Washington Times October 20, 2013
web.archive.org
"John R. Smith letter" (1930s), Wilbur Henry Siebert collection, Houghton Library, Harvard University "Wilbur Henry Siebert Collection". Archived from the original on April 3, 2017. Retrieved January 9, 2014.
Genz, Michelle (March 7, 1999). "Solomon's Wisdom". Washington Post. Archived from the original on October 16, 2005. Retrieved February 19, 2012.
