Paulsen says that he wanted to write a biography of Sally Hemings, a slave who may have been Thomas Jefferson's mistress. He could not find enough information on her to write a biography, but during his research, he found a book of interviews with former slaves. This book inspired Nightjohn, which in its turn inspired Sarny.

Nightjohn is narrated by Sarny, a twelveyear-old girl. An adult male slave named Nightjohn is brought to the plantation of Clay Waller. Nightjohn is an escaped slave who has voluntarily returned to slavery so that he may teach slaves how to read and write. It is his belief that literacy can help make slaves free. Sarny learns to read and write from Nightjohn, and as the novel Sarny makes apparent, she is inspired by his vision of literacy as a weapon for freedom.

A recording of Sarny: A...