The Great Plains / Walter Prescott Webb.

Enhanced descriptions from Syndetics:

This classic description of the interaction between the vast central plains of America and the people who lived there has, since its first publication in 1931, been one of the most influential, widely known, and controversial works in western history. Arguing that "the Great Plains environment. . .constitutes a geographic unity whose influences have been so powerful as to put a characteristic mark upon everything that survives within its borders," Webb singles out the revolver, barbed wire, and the windmill as evidence of the new phase of civilization required for settlement of that arid, treeless region. Webb draws on history, anthropology, geography, demographics, climatology, and economics to substantiate his thesis that the 98th meridian constituted an institutional fault--comparable to a geological fault--at which "practically every institution that was carried across it was either broken and remade or else greatly altered."