Yeah, no.
I'm not even from the US and I know that's false.
Is it true that there was a quite large base of rural agriculture workers even up until WW 2 in america? Yes. That sector fed the country. But they were quite economically insignificant. The strength of the US economy was originally built on the backs of the North East. It was built on trade and industry. Natural resources that weren't food came second. Cash-crops was the economy of the "The South", and that sure as hell wasn't based on white farmers.
Thomas Jefferson might have had a utopic ideal about the small hold farmers taking over the entire continent and sitting fine within their own little communities. However, he also recanted his statement about revolts and revolutions being healthy for a nation after he saw what happened in France.
That's what people have taken umbrage with when it comes to your statement. That you're factually wrong about what built the US. Had it been an agricultural economy it'd never have been able to become the bank capital of the world during the first world war.