Answer: Entrepreneurs lived in these cities and started businesses there.
Explanation:
Before the massive industrial development in the United States' interior, all major jobs were related to port cities. These are the places where the first colonies were founded, so this is the reason why they developed rapidly. The lack of railway infrastructure in the country's interior is the reason why port cities have developed rapidly. The ports were the center of trade and business, so it was in these places that the first industrial capacities were developed. The companies' owners established their companies near the port because all the necessary raw materials arrived by the ships.
The actual number of seats in the house is fixed. The only number that changes is the number of Republicans or Democrats that win them come election time. More seats means a bigger majority for your party.
