<span>The population of the farm in the united states changes between 1950 and today because it dropped from 20 million to fewer than 5 million people. The answer is letter C. Life in the farm is hard, their workload is very high but their rate of return of investment is very low. It did not help with the technology that we have nowadays, machines that can replace certain works that they have and so few of them remains.</span>
In terms of studying that attitude and mentality, it would be helpful to study the journals of someone moving Westward during that time period (mid to late 19th century).