This is meant to be the introduction for the expansion of the railroads, my main article is the highlighted link "Transcontinental Railroad"

The expansion of the railroad system in the latter half of the 19th century in the United States enabled the flow of goods and people to expand to all corners of the country. After the end of the Civil War railroad expansion grew rapidly, culminating in the completion of the Transcontinental Railroad in May of 1869. The railroad system was one of the most important factors in the United States' explosive economic growth and its ultimate status of world superpower by the beginning of the 20th century.