Complex sentence: Smith was born in Sharon, Vermont, but by 1817, he had moved with his family to what became known as the burned-over district of western New York, an area of intense religious revivalism during the Second Great Awakening.
Split into simpler sentences: Smith was born in Sharon, Vermont, but by 1817, he had moved with his family to what became known as the burned-over district of western New York. It was an area of intense religious revivalism during the Second Great Awakening.