Brad Pitt on '12 years a slave'
9 September 2013 Last updated at 19:00 BST
The film '12 years a slave' has been premiered at the Toronto International Film Festival.
The film is based on the memoirs of a New York violinist who was kidnapped and sold into slavery in 1841.
Some of the stars of the film spoke to reporters at the film festival and explained why it is so significant.