The New Jim Crow: Mass Incarceration in the Age of Colorblindness is a book written in 2010 by Michelle Alexander, who apart from a writer is also an American civil rights advocate.
She claims through her work that nowadays, in the age in which all individuals seem to enjoy equal rights after the success of the Civil Rights Movement, this is not exactly true. She points out the existence of massive incarcerations which affect specially African American males, more than any other human group or minority in the US, and how this has become an important source of discrimation. This is why she methaporically calls it, the new Jim Crow.
