Differentiated book- It has a historical context with research of the time-This book contains a historical context, where past events or the study and narration of these events are examined. The historical context refers to the circumstances and incidents surrounding an event. This context is formed by everything that, in some way, influences the event when it happens. A fact is always tied to its time: that is, to its characteristics. Therefore, when analyzing events that took place tens, hundreds or thousands of years ago, it is essential to know the historical context to understand them. Otherwise, we would be analyzing and judging what happened in a totally different era with a current perspective.Across the Plains, with Other Memories and Essays by Robert Louis Stevenson.it is a story by Robert Louis Stevenson. He reviews his 1879 trip to California, very costly for his health. First published as a series of articles in Longman's Magazine in July and August 1883, the story appears in the volume in Chatto & Windus in 1892. .Having completed the Atlantic crossing from Glasgow, under the conditions described in The Amateur Emigrant, Stevenson arrived in New York, traversing the United States from east to west to reach San Francisco, California, after a twelve-day train journey .