A Graphic Summary of American AffficuUure. 7 



The Agricultural Regions. 



The United States may be divided into an eastern and a western 

 half, characterized, broadly speaking, one by a sufficient and the 

 other by an insufficient amount of rainfall for the successful produc- 

 tion of crops by ordinary farming methods. The North Pacific coast 

 and several districts in California and in the northern Rocky Moun- 

 tain region constitute exceptions to this statement. The transition 

 zone which separates the East from the West lies, in general, along 

 the one hundredth meridian, the average annual precipitation in- 

 creasing in this zone from about 15 inches at the Canadian boundary 

 to 25 inches in southern Texas, where the evaporation is much greater 

 and the rainfall more torrential. The East is a region of humid cli- 

 mate farming, based upon tilled crops, small grains, and tame hay 

 and pasture ; the West, of wild hay and grazing, dry farming, win- 

 ter crops in certain localities, and irrigation farming, with only lim- 

 ited areas of ordinary farming under humid conditions such as char- 

 acterize the East. 



The East and West may each be divided into six agricultural re- 

 gions. In the East, precipitation being usually sufficient, the classi- 

 fication is based largely on temperature and the crops grown, while 

 in the West rainfall and topography are the important factors. In 

 the East the agricultural regions extend for the most part east and 

 west, following parallels of latitude; while in the West the regions 

 are determined by the mountain ranges and extend north and south. 

 Agriculture in the East varies primarily with latitude and soils, but 

 in the West the principal factors are altitude and rainfall. The av- 

 erage elevation of the eastern half of the United States is less than 

 1.000 feet; that of the western half, over 4,000 feet. (Compare Fig. 

 2 with Figs. 3 to 16.) 



In the East corn is the leading crop, constituting over one-quarter 

 of the acreage and nearly 30 per cent of the value of all crops. It 

 is grown in all the six eastern regions, but is dominant in the Corn 

 Belt, and is very important in the Corn and Winter Wheat Region, 

 and in the Cotton Belt. Along the Gulf of Mexico and the southern 

 Atlantic coast the type of agriculture varies greatly from section 

 to section — from rice farming to sugar cane growing and winter 

 vegetable production, citrus fruit orcharding, and cattle ranching — 

 so that the region is not named after any crop, but is called the "Sub- 

 tropical Coast,'' because the warm water exerts a controlling in- 

 fluence upon climate and crops. In this eastern half of the United 

 States there is scarcely any cotton grown outside the Cotton Belt, 

 very little winter wheat outside the Corn and Winter Wheat Region 

 and adjacent portions of the Corn Belt and Cotton Belt, and prac- 



