Before revision: Railroad crossing with cattle guards in rural South Dakota upright=1.4|Great Plains of Nebraska Prairie madness or prairie fever was an affliction that affected settlers in the Great Plains during the migration to, and settlement of, the Canadian Prairies and the Western United States in the 19th century.
After revision: Railroad crossing with cattle guards in rural South Dakota upright=1.4|Great Plains of Nebraska Prairie madness or prairie fever was an affliction that affected settlers in theirEuropean Great Plains during the migration to, and settlement of, the Canadian Prairies and the Western United States in the 19th century.