However, two industries benefited the most from the Transcontinental Railroad. Those were cotton and cattle. Railroads made it possible for cotton farmers in the east to ship their products to the western frontier quickly.

Historically, the expansion of the railroads in the 19th and early 20th centuries benefited industrial capitalists (the "Robber Barons") and the federal government the most, though it transformed the lives of millions. Figures like Cornelius Vanderbilt and Jay Gould amassed unprecedented wealth by controlling the movement of goods and people across the continent. For the government, the railroads were a tool for "Manifest Destiny," allowing them to exert control over vast Western territories that were previously inaccessible. On an economic level, farmers and ranchers in the Midwest and West benefited by finally having a low-cost way to ship grain, cattle, and minerals to the lucrative markets in the East. However, this progress came at a massive cost to Indigenous populations, whose lands were seized and whose primary food source, the bison, was decimated by the rail expansion. In 2026, historians view the railroads as the primary engine that shifted the U.S. from an agrarian society to a global industrial superpower.