Ernest Gellner, the late Czech/British philosopher & anthropologist wrote - "It is nationalism which engenders nations, and not the other way around." Gellner also adamantly believed that 19th Century nationalism was the result of industrialism and that agrarian societies are more regional in scope and have a fixed caste system based around the country squires who owned most of the land or a good portion of it. Industrial societies nearly all sprung up from centralized governments with planning involved from the top in variable forms,strengths. The most resistant to industrialization were the country squires, old men of feudalism, who resented anyone above them in status. Consider that that the factories in cities robbed a lot of the peasantry from them who had been previously tied to the lands owned by the squires for generations upon generations.
For all of the horrendous abuses of the factories in the 1800s, overall it created diversity in the economic sphere for the common laboring class, which had previously had almost no choices available to them besides the plow. Since industrialism came from the Top down, people thought in terms of 'nation' outside the manufacturing plant instead of a small regional worldview when their forefathers had toiled for the feudal lord. Though a few country squires later joined the game and became factory owners themselves, overall, industrialization was resented by them as a caste and sought means to halt its growth. Two, factories created a shortage of agrarian labor and the sharecroppers who remained could demand higher wages and perks.
The genus of both industrialism / nationalism was presented to the new America via Alexander Hamilton. Being an immigrant, he was not tied to any of the thirteen original colonies on the Atlantic seaboard. Since he was a disinherited & orphaned illegitimate child, neither was Hamilton a member of any particular class or caste. Thus, he could in effect see the broader picture, and he was the first public servant in America who could have coined the slogan - "it's the economy, stupid!" before the Clinton campaign did in 1992.
AH's arch -nemesis, Thomas Jefferson, was the epitome of a feudal country squire. TJ didn't understand the need for economic diversity and had no problem with the vast inequity of his day. That Jefferson was such a zealous hater of monarchy is more related to his station as a Virginian plantation owner than his reading of the Enlightenment thinkers; he was a patrician who resented aristocrats above him and also those who got just as wealthy as he was via "tricks with paper...and machines". Hamilton's Report on Manufacturers was vilified by the early Jefferson more so than any of the other three pillars of 1st Treasury Secretary's thought.
It should be not astounding that the Jeffersonians developed a romantic veneration to the patricians of the old Roman Republic. Though Hamilton had a classical education himself and often wrote articles with Latin pseudonyms, he thought that the said Roman neoclassical cult was silly just as much TJ's musings about the Anglo-Saxons were. Anyway, the old Romans that Jefferson gushed over were the reactionary plantation owners and those who supported them in the Senate such as Cato and Cicero. Ironically, both of these two famed Romans were also two defenders of the old oligarchy who spoke a great deal about 'liberty'.
Jefferson also had patrician Roman snobbery about 'New Men', those who got fame, power, and wealth outside the established old castes. The Republic, in Jefferson's view, was to be governed primarily by the ones who were there when the Declaration of Independence was written and signed in 1776. Hamilton was seen as the New Man, a young upstart foreigner of low-birth who had a lot of views on things that Jefferson in rare moments of humility claimed not to understand ,i.e., the assumption of debt, National Bank. No wonder that TJ's least favorite Roman was Gaius Julius Caesar, the man who reformed the powers of the plantation- owning Senators; as Hamilton pointed out in correspondence when he responding to accusations that he was both a monarchist and a would- be Caesar, Julius Caesar was a populares Whig in a sea of resentful narrow- scoped optimates, Tories.
Dr. Gellner wrote further regarding nationalism that the United States of America was the "first modern nation that was born modern... didn't have modernity thrusted on it." Jeffersonian Democrats,lead by *Old Men*, resisted this modernity initially. The Federalists, many of them, looked to the future as well as trying to heed lessons of the past. The notion that the USA needed to be a centralized manufacturing nation was regarded as absurd and radical by these Old Men, and a vehicle of statist tyranny. Industrialism and Federalist nationalism was regarded as oppressive largely because they instinctively knew that it meant the beginning of the end of their regional agrarian caste, an edifice the Jeffersonian States Righters called - liberty.