Libraries are in the crossfire yet again, as conservative groups mount a historic number of challenges to books to remove from public book shelves literature dealing with race, racism and LGBTQ identity. The book-ban campaigns have turned so nasty that some librarians have lost or left their jobs.

But it’s not the first time library workers have faced anger, as evidenced by the embattled librarian-activists who ran “freedom libraries” during the Freedom Summer of 1964.

Freedom libraries were an invention of the Council of Federated Organizations, a civil rights supergroup that merged the efforts of the Student Nonviolent Coordinating Committee, the Congress of Racial Equality and the NAACP. In the lead-up to Freedom Summer, during which more than 1,000 Northerners flock to Mississippi to help local Black activists in registering as many Black voters as possible, organizers saw an opportunity in schools and, particularly, libraries.