What area of the colonies contained the most settlements?

Settlements within colonies tended to cluster around rivers and sea ports, especially in the early colonial era. This clustering was largely due to transportation needs. Without cars or trains it was difficult to engage in long distance transportation over land. Land transportation was expensive and took significant amounts of time. By contrast, sea and river travel were easier and less expensive. Cities developed around rivers and sea ports in order to facilitate the sale of excess crops and the importation of luxury goods and other staples. Exporters had to congregate in these areas to lower the costs of transport. Importers congregated in the same areas for the same reasons. Jobs related to manufacturing, curing tobacco, and other product finishing tended to move toward ports as well, to lower their shipping costs. Basically, any individual that was not focused on farming or exploration would congregate near cities that centered around water travel lanes.