US historical yield per acre
how many people does each farmer
For 1800 the number would be about 5 people, but note the problems of counting farmers rather than farm families

late 19th century farmers used plenty of complex technology
in the early 20th century some farmers began to pull that technology with a tractor instead of horses or mules

Education and research:
Morrill Act and USDA
1887 Hatch Act provided federal funding for research stations in each state
1906 Adams act: doubled funding for research stations but at least half must be used for original research
1914 Smith Lever Act provided federal funding for agricultural extension agents, already established in many states
1917 Smith-Hughes Act provided federal funding for vocational education (including agricultural education) in high schools
    led to the founding of Future Farmers of America clubs

Farmers wanted a guarantee of a fair price for their crops, protection from prices collapsing because of overproduction.  But how to achieve that?