It shows the lessons he learns from his master, his mother, and the land that would become Texas, and how he becomes the honorable man he is in the future.
The second part is about his time living with the Native Americans where he learns the skills to make him the great U.S. Marshall that is the third part of his life. Examples of his many searches, arrests, and even some killings make up the last and shortest part of book.
Paulsen’s forward shows his contempt of the other “heroes” of the time, and his book shows what he thinks a real hero is like.