What makes each city unique?

I’ve been very interested in cities for the last couple of years because of the vast personalities they have. I always look at the scenery within the cities I visit and I also look for the aspects that make the city unique such as the music that is created by the people within that city. I know that each city has a different demographic and different kinds of people who live in the city. I would like to know how cities start, how they develop and what comes from the major cities.
When cities were first developed in America they were started “in locations where nature offered various attractions, such as on coastlines where the land's contours created harbors, on rivers and lakes that could be used for transportation, water supplies, and waste disposal, and in fertile river valleys with extensive food and animal resources” (“The city and the natural environment” 1.) These natural resources are vital towards the development of cities because without them cities would not be able to run with the efficiency that they do. However, natural environment is not the only that makes a city unique.