Final answer:
Railroads and trains changed life in America by transforming the economy, facilitating industrial expansion, and connecting people and goods across the country.
Step-by-step explanation:
The development of the railroad infrastructure in the 19th century had a significant impact on American life. Railroads transformed the American economy by linking port cities to the interior, creating a national market system, and fueling industrial expansion. They also facilitated the growth of urban centers and led to the disappearance of craft industries and small shops as people went to work in factories. Railroads played a crucial role in the transportation revolution, making travel faster, more accessible, and less expensive, which contributed to the market revolution and connected rural families to the wider world.