What factors contributed to the growth of us industrialization

Transcontinental railroads and immigration contributed to industrialization.

Explanation:

Goods that have once been produced by hand are now produced by industries. After civil war, there was reconstruction era and this paved way for industrialization. Belief of America that it is gods' destiny to expand the borders paved way for setting up huge industries in the vast lands which acquired huge profits for the economy to develop.

Rich natural resources, new transportation system, mechanization and minimum intervention of government in trade perspective ensured supported industrialization, the upcoming factory system also contributed for industrialization.