Why might the author of "A White Heron" have chosen to set the story in the country?

Sarah Orne Jewett's "A White Heron" is a work of regionalism, meaning it is set in a particular region of the United States and attempts to replicate life in that region. This is part of the reason that Jewett's story is set in the country: she is giving a realistic depiction of life in the rural land of the Northeastern United States.
Beyond its genre distinction, "A White Heron" focuses on its protagonist's connection with the natural world, symbolized through the titular heron. Sylvia is a young girl who lives and works in the country of the Northeastern U.S. She is first seen in the woods "driving home her cow." Her relationship with nature is already established from the first paragraph of the story. Later, a hunter arrives at the home where Sylvia lives with her grandmother. He is searching for a rare white heron. Sylvia likes the hunter and wants to help him, but she is torn between him (representative of society) and her connection to the natural world around her (obviously representative of nature). Eventually, Sylvia honors her prior relationship with nature, which could also suggest that the author seeks to connect those who live in this rural setting of the Northeast to the natural landscape around them, implying they prefer to live amongst nature than to dwell closely with other people in society. The story ends with a reflection on Sylvia's "Dear loyalty" to nature, and the narrator implores the birds of the country to "tell your secrets to this lonely country child!" The final line of the story not only solidifies but also further strengthens Sylvia's bond with her environment.