How did railroad expansion affect the growth of major urban centers

Traveling to and from major cities became easier.

Explanation:

The expansion of the railroad gave people the opportunity to travel on faster and cheaper transportation. This made it easier for people to gain access to large urban centers and to move there in search of job opportunities and a better quality of life.

This has increased the population rate in urban centers, and the success of the railroad has allowed urban centers to be increasingly filled with factories, businesses and shops.