What was a major effect of the agricultural revolution in the united states during the late 1800s?

The major effect of the Agricultural Revolution in the 1800s was the increase in the food supply, which was able to feed the urban dwellers. Any family who agreed to settle on a land for at least five years was given that land for free. The farmers were isolated from each other due to large acres of land each farmer owned. Farmers started buying machinery for agriculture and were in debt and severe competition prevailed. The conditions of the farmers became harsh and a political movement started for the farmers. The productivity still increased and the population of the US also doubled. 

Cwould be the answer