Twelve Years a Slave was such a popular book when published in the 1850s, and so treasured by owners, that early editions are readily available (though often in very worn condition). Occasionally copies are offered on ebay.com at reasonable prices, Also, copies can usually be found at Abebooks.com:
Early editions from 1850s, AbeBooks
Though Twelve Years a Slave faded from mainstream awareness in the 20th Century, it was not overlooked by Chaplain T. G. Steward in his 1913 review of African American writers in African Methodist Episcopal Church Review (though he does spell Northup incorrectly).
Three annotated versions have been published:
One, put out by Lousiana State University Press in 1968 and edited by Sue Eakin and Joseph Logsdon, is widely available (often economically available from eBay sellers). It's available from Amazon: LSU edition on Amazon
A 2007 hardcover edition titled Solomon Northup's Twelve Years a Slave and Plantation Life in the Antebellum South , by the late Sue Eakin (whom I assisted slightly and who credited me in some of the footnotes) is no longer in print, but paperback, audio book and e-book versions of this title are offered. See: Twelve Years a Slave, by Dr. Sue Eakin and Louis Gossett, Jr.
In 2016, W. W. Norton published a Norton Critical Editions version, which includes the original text with annotations, as well as ancillary material, such as a timeline and articles, essays and book excerpts related to Solomon Northup. It was edited by Henry Louis Gates, Jr., and Kevin Burke. I assisted by providing some editorial feedback, and am credited in a few places in the book. See: Twelve Years a Slave, Norton Critical Editions.
Because the book was published about 160 years ago, it is in the public domain, which means it is not copyrighted, and anyone can republish it (online or in print). With announcements of plans to create a new film adaptation of the book, many publishers, large and small, have recently created editions, in printed, e-book, and audiobook formats. Use the following link to check amazon.com for current editions of Twelve Years a Slave:
Twelve Years a Slave on Amazon
Some publishers have added some value to their editions, mainly by adding pertinent illustrations. Here is a short (but, by no means comprehensive) list of illustrated editions:
Illustrated edition, Martino Fine Books, 2010
Quaint Press, 2012
Quid Pro Books, 2012 Kindle edition
Illustrated version by Randy DeCuir, 2013
In 2013, publisher Entremonde published a French translation of Twelve Years a Slave
A great companion book to Twelve Years a Slave is: Solomon Northup: The Complete Story of the Author of Twelve Years a Slave, published in 2013. Information at Solomon Northup page
In the 1980s, PBS produced a television adaptation of Northup's book, called "Solomon Northup's Odyssey" (also known as "Half-Slave, Half-Free"). Avery Brooks appeared as Solomon Northup, and the film was directed by Gordon Parks. Videos of the film can be purchased from various online vendors, including Amazon
In 2012, a screen adaptation of Northup's story was filmed in Louisiana, directed by well-known British filmmaker Steve McQueen. Chiwetel Ejiofor plays the role of Solomon Northup, and the cast includes many notable performers, including:
Michael Kenneth Williams, and
For a list of the complete cast and crew see:
12 Years a Slave, IMDB cast and crew list
The film was released in October 2013.
Watch the Standard-Definition trailer (requires Apple QuickTime)
Watch this featurette about the making of the film 12 Years A Slave from Fox Searchlight.
See the film's Production Notes
Full biography of Solomon Northup, Solomon Northup: The Complete Story of the Author of Twelve Years a Slave.
Information at Solomon Northup page
Solomon Northup was the most well-known kidnapping victim, but he was by no means the only one. The 2016 book, Solomon Northup's Kindred: The Kidnapping of Free Citizens before the Civil War, tells about many others who were kidnapped and sold into slavery. The book also provides historical background that explains why kidnappers were able to operate with relative ease.