12 Years a Slave is based on the 1853 autobiography of Solomon Northup, a free black man who was kidnapped in Washington D.C in 1841 and sold into slavery. He worked on plantations in the state of Louisiana for 12 years before his release. 
I always was a sucker for true stories and tales about the abusive system of slavery. I guess my inner human rights activist needs a reminder once in a while that we have to do all we can to prevent or stop slavery today. A look into the past never hurts, though I’d like to see slavery from other countries and eras depicted as well. There are also several Hollywood stars in the movie, so this is another incentive to watch the movie.
 Source and movie link: Wiki