Seventeen-year-old Canadian immigrant James J. Hill arrives in St. Paul, Minnesota. Working song the waterfront, he immerses himself in the Mississippi River trade and, within ten years, starts his first business. An opportunity strikes when the St. Paul and Pacific Railway goes bankrupt for the third time. Hill convinces a group of associates to make a play for the railroad.

Hill takes the biggest gamble of his career. He decides to build west, despite existing transcontinental lines to the north and south. To get there, he must cross two mountain ranges, lay hundreds of miles of track, and convince Congress to gain access to Indian territory.

Hill faces striking workers and American Railway Union President Eugene Debs. Hill recruits JP Morgan to add the Northern Pacific to his empire. A fight for control of the Northern Pacific pits Hill against railroad tycoon E. H. Harriman in an epic stock battle that sends Wall Street into a tailspin. A young President, Theodore Roosevelt, seeks to curtail Hill's power.

Hill turn Seattle into an international port by opening up trade with Asia. Encouraged by Great Northern agents, immigrants from Europe, settle in Montana and North Dakota. Hill expands into Oregon, facing Harriman once again in "The Last of the Great Railroad Wars." Hill's son, Louis, takes the reins of the Great Northern and develops Glacier National Park. Hill backs environmental conservation and secures a loan to the Allies during World War I.