Just as it opened the markets of the west coast and Asia to the east, it brought products of eastern industry to the growing populace beyond the Mississippi. The railroad ensured a production boom, as industry mined the vast resources of the middle and western continent for use in production.
Considering this, what did railroads do?
It made commerce possible on a vast scale.
In addition to transporting western food crops and raw materials to East Coast markets and manufactured goods from East Coast cities to the West Coast, the railroad also facilitated international trade.
Moreover, why was the railroad so important? The railroad opened the way for the settlement of the West, provided new economic opportunities, stimulated the development of town and communities, and generally tied the country together.