Unfortunately, Jennifer Donnelly has never shared explicitly why she chose this title or the meaning behind it. As with all parts of a text, they are open to interpretation!
A Northern Light is a work of young-adult historical fiction, set in the year 1906 in Upstate New York. The story follows Mattie Gokey as she struggles with her obligation to work on her father's farm and her dream of becoming a writer. Along the way, Mattie takes up work at a nearby hotel where out-of-town people like to spend their summer vacations. Mattie is pulled into the mysterious death of a young woman named Grace Brown, and she is the only person who can really find out what happened to her. The bulk of the book takes place over just a few days, but Donnelly stretches out the story with intimate details of people's thoughts and feelings. This coming-of-age story is a truly powerful read!
The title, A Northern Light, plays off of a phrase many people are familiar with-- the northern lights. This is another name for the aurora borealis: the electron activity that takes place in the night sky near the poles of Earth, creating beautiful displays of light and color. However, light need not be taken so literally; it can also mean a source of inspiration or hope. Mattie's life can seem pretty dark and dreary at times. She is responsible for much of the work on the farm, as well as the care of her younger sisters, and she's studying for exams! With so much on her plate, she feels overwhelmed and trapped. When Grace Brown comes into her life and Mattie comes to know her posthumously through her letters, Mattie realizes the importance of the opportunity that has been offered to her. The book ends with Mattie saying, "I have to, because she can't." Though she doesn't say explicitly who can't do what, one can interpret that Mattie feels a sense of duty to Grace Brown's memory. Mattie identifies with the dead Miss Brown, who was also young, plain, and in love with a handsome boy. Mattie, like Grace, felt trapped by the possibilities of her life-- did she really want to be a wife and mother with no time to read and write? Or worse, an unwed mother? I think that Mattie was inspired to go to college and become a writer in honor of this girl's life. She would not participate in the legacy of young women having their dreams squashed by societal obligations.
Northern refers very much to the setting of the book. The Adirondack region of Upstate New York is referred to as the North Woods in the book.