Final answer:
The introduction of railroads for transporting items led to significant changes in the United States, including the rapid growth of the railroad industry and the acceleration of development in other industries. Railroads provided an efficient transportation system that facilitated the movement of raw materials and finished goods, contributing to the nation's economic growth.
Step-by-step explanation:
The introduction of railroads for transporting items led to significant changes in the United States. The railroad industry became the nation's first major business, and the expansion of railroads stimulated the growth of industries such as iron, wood, coal, and more. Railroads played a crucial role in accelerating the development of various other industries, as they provided a powerful and efficient transportation system. The railroad network expanded rapidly, covering almost every corner of the country by 1890. This expansion allowed for the transportation of raw materials to industrial factories and finished goods to consumer markets, contributing to the nation's economic growth.