I suppose to be fair, the first date would have to be 1800, when Ricardo was still alive. However, I agree that the U.S. was at least 50 years behind Britain in industrialization, up until perhaps 1850. I suspect it was more a matter of population than anything else; even in eastern New England, the population was pretty low in 1800. Massachusetts had fewer than 500,000 people, mostly farmers. Sure, they could put up a mill, but why bother? The standard of living even for regular farmers was astoundingly high at the time.

Look at this house that Bronson Alcott lived in in Concord, for example. And he was broke most of the time.