(iv) In the early years, the fertile soil produced good crops. When the soil became impoverished in one place, the migrants would move further west to raised new crop.(v) It was however, only after the 1860s that settlers swept into the Great Plains across the River Mississippi. In subsequent decades the region became a major wheat producing area of America.
(vi) From the late 19th century, there was a dramatic expansion of wheat production in the USA. The urban population in the USA was growing and the export market was becoming ever bigger.
(vii) As the demand increased, wheat prices rose, encouraging farmers to grow more and more wheat.
(viii) In 1910, about 45 million acre of land in the USA was under wheat. Nine years later the area had expanded to 74 million acres. Now, the USA began to be called the 'bread basket of the world'.
(ix) But it could not maintain this image for a long period. The expansion of wheat production in the Great Plains created severe problems.
(x) In the 1930s, terrifying dust storms began to blow over the Southern Plains. Black blizzards rolled in very often 7000 and 8000 feet high, rising like monstrous waves of muddy water.
(xi) They came day after day, year after year, through the 1930s. As the skies darkened and the dust swept in, people were blinded and chocked.
(xii) Cattle were suffocated to death, their lungs chocked with dust and wind. Dead bodies of birds and animals were scattered all over the landscape.
(xiii) Tractors and machines that had ploughed the earth and harvested the wheat in the 1920s were now clogged with dust, damaged beyond repair. The whole region had become a dust bowl. The American dream of a land of plenty had turned into a nightmare.