I would say that it is the fertile soil, the question seems incomplete though
One factor was barbed wire. As farmers and ranchers wisened up, they used the wire to fence in their cattle, destroying the use of cowboys, and taking away one aspect of the "wide open west".
Herds of cattle took over the plains and destroyed the grass. In 1883 t big drought struck and water streams dried up and prairie fires grazed. Also the barbed wire and the natural disasters. People wanted to be able to mark their property.
Medieval doctors learn treatment from Romans
This might be wrong cause I don't know which lesson but if it was a while ago like before the 1980 it was because children were forced to work and they would get hurt and still be forced to work so it would be slow. But if it is no in the 2000 it is because people are not getting paid enough so they don't wanna work and are working slow
