The city was the basic building block of the modern democratic nation-state. The cities provided the mercantile intercourse without which any amount of innovation in the countryside would have been meaningless. Cities absorbed, distributed, and ultimately demanded improvements in agricultural output, eroding the feudal economy and fueling improved production within the city walls.
The city walls were not defenses for times of war, but for times of peace. To do business in the city, you had to enter the city and play by their rules. They went to a lot of expense to create the market, had every intention of being successful, and felt fully entitled to make their own rules.
How much expense? Enough to survive sieges, both of the military and economic variety. Enough to build cathedrals that reigned in height until the era of the skyscraper. Enough to transform the economy of surrounding regions and distant lands. Enough to defy the landowning nobility and make kings their debtors.
Because cities were corporations of commoners, and because the productive forces were pent in city walls, real forms of democracy emerged- enough, at least, to ensure that any prolonged starvation of the workers would be rewarded with destructive urban rioting. A crude tool, but, over time, sufficient.
This is important because cities harnessed the forces of 'market capitalism' by unashamedly regulating and taxing markets- markets that could not have existed in a 'state of nature'. The proposal is that the US of A is, in fact, a market that we have every right to control democratically- and that "To secure these rights, governments are instituted among men, deriving their just powers from the consent of the governed..."
This is our market. We've spent trillions creating it, surrendering vast amounts of personal agency in the process, but, strange to say, usually at great benefit to ourselves and others. No imaginary "invisible hand" has ever come anywhere close to the ability of democratic government to create value. The history, first of the city-state, and then of the nation-state, illustrate this, but what will come next, in the context of global warming?
That is hard to tell, but putting our own house in order would be a good first step in preparing to deal with whatever it may be.