The Prologue is a letter written in November 1899 from Catherine Hall Onesti to her great-granddaughter and namesake, another Catherine. The older Catherine is currently living in Providence. In the letter, Catherine explains to the younger Catherine that she is giving her the journal for her 14th birthday. The older Catherine turned 14 in the last year of the journal, 1831, the same year in which her father remarried; she lost her best friend, Cassie; and she left the farm. She tells her great-granddaughter that although Cassie will never grow old, she understands that life is all about changing, and she hopes that the younger Catherine will not be afraid of, or waste, her life.

Chapter 1 includes journal entries from October 17 to November 7, 1830. In the first entry, Catherine states that she is 13 years, six months, and 29 days old and lives in Meredith, New Hampshire. The book was a gift from Father, Charles Hall. Her mother has been dead for four years, and she has a younger sister named Mary Martha (called Matty in the rest of the story) and a best friend, Cassie Shipman, who is a year older than Catherine.