the earliest large cities were located on waterfronts. How might new changes in transportation affect the location of cities ?

Ships is the obvious answer.

Study the building of the railroads. How did things change once railroads went from coast to coast? How did people decide where to build railroads? Were some towns left out and others included? What do you think resulted from that?

Study the building of roads and highways. in particular, what changes occurred because of the building of the Interstate Highway system begun by President Eisenhower?
http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=interstate+highway+system

What other forms of transportation have there been in the history of this country? Research those, too.

New changes in transportation can have a significant impact on the location of cities. Traditionally, the earliest large cities were located on waterfronts due to their importance in facilitating trade and transportation by sea. Waterways provided a means of transportation for goods and people, making it advantageous to establish cities in close proximity to the water.

However, with the advent of new transportation technologies, such as railways, roads, and air travel, the reliance on waterways for transportation has decreased. As a result, cities have been able to expand their locations beyond waterfronts. Here's how new changes in transportation can affect the location of cities:

1. Railways: The development of railways enabled cities to grow and expand inland. With rail networks becoming more widespread, cities could be built at locations where trade routes crossed, allowing for better connectivity and trade.

2. Roads and Highways: The improved road networks, including highways, have made it easier for cities to be located further inland, away from water bodies. The accessibility offered by well-connected roads has reduced the necessity for cities to be solely reliant on waterfronts for transportation purposes.

3. Air travel: The emergence of air travel has reduced the significance of distance and physical barriers. Airports can now serve as major transportation hubs, allowing cities to flourish even in landlocked areas. Air transportation has effectively transformed how cities are connected globally, overcoming geographical constraints.

Overall, new changes in transportation have enabled cities to be more flexible in their location choices. While waterfronts still hold importance for certain cities, particularly those with major international ports, new transportation options have expanded the possibilities for cities to thrive in various locations, including inland regions.