When the Framers were meeting, New York City had less than 10% of the population of the whole state. NYC, Philly, and Boston combined had less than 100,000 people out of nearly 4 million; only 5% of the entire population of the country lived in towns with a population of 2,500 or more.

With about 95% of the population being rural, there was no danger of cities dominating the political affairs of the country. The Framers at the Constitutional Convention did very briefly (on August 7th, 1787 — see p.167 here of Farrand Vol. 2) discuss the idea of requiring voters in federal elections to own some amount of land in their own name. The idea was that urban voters would be easily bribed or coerced into voting a particular way.

My read of Madison’s notes is that Benjamin Franklin shot down the idea. After he gave his speech, the vote went 7–1–1 against. Delaware’s delegation voted in favor and Maryland’s delegation deadlocked; the rest of the delegations that were present that day decided that urban voters deserved every bit as much of a say.