How did the USA become the bread basket of the world? Explain. Or "Plant more wheat, wheat will win the war"

How did the USA become the bread basket of the world? Explain.
Or
"Plant more wheat, wheat will win the war". Who said these? What led to dramatic expansion of wheat production in the USA?
Explain any three causes for dramatic expansion of wheat production in the USA from the late 19th century.

From the late 19th century, there was a dramatic expansion of wheat production in USA. The growing urban population and export market encouraged the farmers to produce more wheat. President Wilson encouraged the farmer by saying ‘Plant more wheat, wheat will win the war’. The three causes for dramatic expansion of wheat production are
(i) Displacement of tribes and spread of railway By the early 20th century, the landscape of USA had transformed radically. White Americans had moved Westward and established control upto the West coast by displacing local tribes. They wanted to make the entire landscape into different agricultural belts. They also wanted to dominate the world market in agricultural produce.
After the 1860s, the setders swept into the Great plain across the Mississippi River. In subsequent decades the region became a major wheat producing area. The spread of railways made it easy to transport grain from the wheat producing region to other regions.
(ii) Growth in demand for food grain By the early 20th century, the demand became even higher and during the First World War the world market boomed. As Russian supplies of wheat were cut off, the USA had to feed Europe.
In 1910, about 45 million acres of land in the USA was under wheat production, within 1919 it expanded to 74 million acres.
(iii) Introduction of New Technology The introduction of new technology helped farmers in the Great plains to increase the production of wheat to meet the demand of world market. In this way, the USA became the bread basket of the world.