Before any of the farm inventions were invented, farmers had to do things the hard way. Every one of them had to hire slaves, or go out by themselves to harvest their crop. People wanted on easier way to farm. When Jethro Wood invented the iron plow, many people could build off of his idea. John Deere made a lighter plow out of steel which could be pulled by horses and more work would get accomplished fewer people.
The Inventions of the plows allowed farmers to produce more crops. Since farming became easier many people wanted to expand their land for more crops. this lead to the settlement of the west.