Complex sentence: As a result of the war, nearly all Mormons in Missouri, estimated at more than ten thousand, were forced to leave the state and most settled in or near what would become the city of Nauvoo, Illinois.
Split into simpler sentences: As a result of the war, nearly all Mormons in Missouri, estimated at more than ten thousand, were forced to leave the state. Most of these refugees settled in or near what would become the city of Nauvoo, Illinois.