In the late 1800 which factor. Directly contributed to the growth of heavy industries in the US?

In the late 1800s, the growth of heavy industries in the U.S. was significantly driven by the availability of abundant Natural Resources, such as coal, iron ore, and oil. The expansion of the railroad network facilitated the transportation of these raw materials and finished goods, further stimulating industrial growth. Additionally, technological innovations and an influx of immigrant labor provided both the skills and workforce needed to support burgeoning industries like steel and manufacturing. Together, these factors created a robust environment for industrial expansion during this era.