Question

How did the completion of the Transcontinental Railroad affect companies that made products?
Companies could hire people who worked in different states.
Companies could build factories in the rural West.
Companies could expand into the South.
Companies could ship goods cheaply over long distances

Answer 1

Companies could ship goods cheaply over long distances.

The transcontinental railroad dramatically lowered transport costs and transit times, opening national markets for manufactured goods. (It also made labor and raw materials more mobile and encouraged westward industrial development, but the primary direct effect for manufacturers was far cheaper, faster long‑distance shipping.)