What factors encouraged American farmers to undertake an expansion of wheat production?

The factors which encouraged American farmers to undertake expansion of wheat production were:

(i) The expansion of White Americans in the Great Plains made available large tracts of virgin land suitable for wheat cultivation.

(ii) The demands of the growing urban population and booming export market.

(iii) Increase in wheat prices.

(iv) Spread of railways made possible transportation of grain from wheat growing regions to the eastern coast for export.

(v) In the wake of World War I supplies of wheat from Russia were cut off to Europe. The US farmers responded to the need of the time by undertaking increased wheat cultivation.