Years ago, Slate produced a great interactive map where you could view the US, county by county, and see what percentage of that state's population were farmers. I forgot what the methodology was, because sometimes people live on farms but aren't farmers, and sometimes people work on farms but live elsewhere (including in cities). The map seems to have been lost, but from what I remember, in states like Ohio, the highest percentage of farmers in any county was around 10%.
Even that can be a bit deceptive, because the USDA considers a farm anything that could produce $1000 dollars worth of crops a year. A suburban house on a large lot with a dozen apple trees is a farm---even if there is no actual harvest.
https://fivethirtyeight.com/feature...d-most-small-farms-arent-really-farms-at-all/
This has been an issue in American politics since the beginning. Thomas Jefferson thought the country didn't need to develop infrastructure, because in his mind, the US was a nation of independent, self-sufficient farmers. The thing was, even in the 1700s, this was already more a dream than a reality. But the myth persists, and there are plenty of places where people think of themselves as living in farm country---while living in commuter suburbs where they travel to work in offices.
And from a train point of view, if you look at areas like Cleveland-Cincinnati or Houston-Dallas, that currently don't have train service---those are both large cities within a short geographical distance, with not many terrain barriers. Those areas have population densities not that much less than the NEC, which has dozens of trains per day. And, of course, California's central valley, which is an area with many agricultural workers and farms, has regular corridor train service. And soon will have high speed rail!
So I guess my point overall is that rural, and agricultural, are words that have a denotation and a connotation. The average American might think of Ohio or Texas as rural, agricultural states where many people live on or near farms---but objectively, that isn't true.