To write an essay on Sam Patch, the Famous Jumper, consider what topic in the book interests you the most and then develop a thesis that you can support with evidence from the text.
One argument to consider would be that Sam's daredevil nature could have helped him escape a life of factory work and poverty. People who grew up like Sam often went to work in the mill and weren't able to provide a better life for their future families than the ones they grew up with as children. There was little social mobility. Since Sam was willing and able to impress people with his daredevil stunts, he may have changed the course of his life if he hadn't died. You could write about what this meant for him and what his life might have been like otherwise.
Another argument to consider is what about Sam made him a daredevil. Look at the statements he makes, the views of the people around him, and the things he does to gather evidence. Then you can chart his growth as a person and a thrill seeker. Ask yourself what qualities led him to make such dangerous jumps.
Finally, you could look at how people considered Sam versus how he saw himself. The author argues that at some point, Sam was more interested in being a showman than anything else. His original jumps may have been done to make a point about a building project that was only going to help wealthy people. Still, even after his career progression and death, some people saw him as a champion of the workers and the poor. Look at evidence from Sam's life and the text to determine which you believe him to be and why. Is it possible that he was both?
Use evidence to support your argument and end the essay with a strong conclusion that sums up your point.