On his journeys, he makes stops to learn how places, events and people, and the railroads of the 19th century influenced the country's growth into a major superpower.

In his first series, Portillo took two railroad journeys in the north-east of the United States, spanning a total of 15 episodes.

[3] In his second series, Portillo took two railroad journeys around the midwestern and central regions of the United States, spanning a total of 20 episodes.

The episode order was also changed, with the Reno to San Diego journey first, followed by that from Boston to Toronto.

A book to accompany the series, written by Michael Portillo and published by Simon & Schuster UK, was released in February 2017.