Here are a few possibilities:
* The decision to move: The book opens with the Ingalls family living in a small Kansas town, but they decide to move westward to seek a better life. This decision sets the entire journey and story in motion, making it a strong contender for the inciting incident.
* The first night on the prairie: While the family has decided to move, it's their first night camping on the prairie, exposed to the harsh elements and the unknown, that truly marks the start of their new life.
* The arrival at their new home: The family's arrival in the Kansas territory, where they face challenges with building a home, dealing with the unfamiliar landscape, and encountering new people, could also be considered the inciting incident.
Ultimately, the "inciting incident" is a matter of perspective. Each of these events significantly influences the family's journey and the story that unfolds.