The reason why the railroad expansion increased the populations of major urban centers during the Gilded Age was Traveling to different cities and factories became easier.
The Gilded Age saw the expansion of the railroad networks of the nation which led to more people being able to access the different cities that the railroads led to.
This allowed for people to be able to move to cities easier and take up jobs in factories which was a key characteristic of the Gilded Age.
Find out more on the Gilded Age at https://brainly.com/question/28145617
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