The disturbing correlation between the way in which today’s U.S. prison system is run and the systemic racism that fueled the Jim Crow era is without question.

From Ava DuVernay’s compelling documentary 13th, to the countless other programming and literature that examine the disproportionate targeting of African-Americans by the U.S. justice and prison system, there’s never been more opportunities for people to learn more about the dark history behind it all.

But there have also been many not-so-subtle roadblocks put in place to keep those who would benefit most from learning more.

Recently, it was revealed that the New Jersey Department of Corrections placed a ban on the reading of the book, “The New Jim Crow,” by Michelle Alexander, which focuses on impact of mass incarceration on the Black community. When asked, New Jersey DOC spokesman Matthew Schuman reportedly declined to elaborate on the reasoning behind the ban, according to the New York Times.

The ACLU sent a letter to the NJ DOC in response to the book being banned, calling it unconstitutional and noting that it was in direct violation of prisoner’s first amendment rights.

“For the state burdened with this systemic injustice to prohibit prisoners from reading a book about race and mass incarceration is grossly ironic, misguided, and harmful,” the ACLU wrote. “It is also unconstitutional.”

As a result, the New Jersey DOC announced on Monday that the ban on “The New Jim Crow” has been lifted, adding that it is currently “reviewing its’ policy on banned materials for appropriate revisions,” according to an NBC News report. Shuman also noted that the book was removed from the list because it should not have been banned in the first place, as it is used in a college-level course that is currently offered to inmates.