In the prefatory note, Stevenson's wife describes the process that led to Stevenson's writing Kidnapped. While researching for a play his wife planned to write, Stevenson had come upon a description of the trial of James Stewart for the murder of Colin Campbell of Glenure. According to his wife, Stevenson had always been interested in the period, and decided to write a story that would hinge upon the Campbell murder. It would feature as its protagonist a boy named "David Balfour" that was supposedly an ancestor of Stevenson himself, who would travel through Scotland "as though it were a foreign country." Stevenson's wife notes that he followed the article's description of Alan Breck Stewart very closely, and that, when they visited the site of the murder more than a hundred years after it occurred, bitter feelings were still felt between the Stewart and Campbell clans.
The book is dedicated to Charles Baxter, a friend of Stevenson's. In the dedication, Stevenson admits that there are a few inaccuracies in his novel, such as the year that the murder of Colin Campbell took place, the nearness of the Torran Rocks to the island of Earraid, and the absence of a "David Balfour" from any record of the Campbell trial. Stevenson apologizes but admits that he isn't particularly interested in accuracy, but writes the story for the pleasure of schoolboys.
The Prefatory Note serves as the only real historical information the reader gets outside of the story. It establishes the fact that the murder of Colin Campbell was a historical event, as was the existence of a man named Alan Breck Stewart. It also informs us that David Balfour is a fictional character intended to be a descendant of Stevenson, and that part of Stevenson's plan for the story is to have David travel through Scotland "as if it were a foreign country."
This idea of portraying Scotland as a foreign country is an important one. Kidnapped is an adventure book that focuses very much on travel. Treasure Island takes place primarily in two places: a ship and the island of the book's title. Kidnapped, on the other hand, moves from the Lowlands of Scotland, to a ship, to the west of Scotland and then all the way across the Highlands—through forests, plains, and moors—before finally returning to the Lowlands. During the course of the novel, David meets many characters of different backgrounds and social status. To many readers—even in Stevenson's time—the Scotland of Kidnapped must have seemed like a wild, unfamiliar land, full of rogues such as Alan and the dangerous soldiers who are hunting them down.
In the dedication, Stevenson claims that his primary motive for writing the story is for the pleasure of schoolboys, giving them a break from their studies. He makes fun of the few inaccuracies of his text, but in fact Kidnapped was fairly well researched and includes a great amount of realistic description. Also, while the book may have originally been published in Young Folks magazine, it is written in a style that can entertain both adults and children, and the Jacobite-Whig struggles between David and Alan cannot have failed to interest historically- or politically-minded adults.