Telling a story isn’t simple. You can blandly say: Paul was a poor migrant living in Oklahoma.
And that has no effect on you. Nothing.
Famous and well-told works of writing follow through with back story. It’s main focus is supported with small details that bring its characters and setting to life. It’s more than to just say something–writers must show it. They must use and create evidence to do that–whether it be evidence of non-fiction or fiction.