Question

The geographic location of these cities made them economically influential because they were...?

Answer 1

Port cities - trade/travel import/export
Farming communities - growing goods (corn, wheat, sugar, indigo, cotton etc.)
Industrial centers - Job opportunities, manufacturing of products like textiles, steal/metal, cars, boast steel etc. (industry provides buts more money and more services for the economy leading to higher income per capita and more labor productivity)
Military outpost - employment opportunities, protection, supplies (States and communities also benefit from defense contracts with private companies for equipment, supplies, construction and various services such as health care and information technology.).