What made the biggest impact on American industrialization?

The biggest impact on American industrialization was the expansion of the railroad network, which facilitated the rapid movement of goods and people across vast distances. This interconnectedness spurred the growth of industries such as steel and coal, while also enhancing access to markets. Additionally, technological innovations, such as the telegraph and assembly line, significantly increased productivity and efficiency. Together, these factors transformed the American economy from agrarian to industrial, laying the foundation for modern economic growth.