The story of the quiet revolutionaries who made a simple idea of a public library happen. From the pioneering women behind the "Free Library Movement" to today's librarians who service the public despite working in a contentious age of closures and book bans, meet those who created a civic institution where everything is free and the doors are open to all.

TV's most-watched history series brings to life the compelling stories from our past that inform our understanding of the world today.