As the title implies, the novel is based on the actual American Library in Paris, primarily during WWII. The Library becomes a safe haven for Odile Souchet, her book-loving coworkers, and their French and ex-pat subscriber/patrons in the midst of war.
A secondary timeline in 1983 Montana features widowed war-bride senior-citizen Odile and Lily, her teen next door neighbor. Odile sets aside self-isolation to help Lily through a challenging time, and the impact on both is life-changing.
I enjoyed many aspects of this story, especially the fact that real people in history inspired Odile's American Library colleagues and patrons. I particularly loved how Dewey Decimal classifications weave the characters and timelines together.