The transcontinential railroad allowed for more westward expansion.
Explanation:
With westward expansion on the boom the railroad allowed for more supply, people, and the the economy west. 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
If your teacher selects you to speak on behalf of your class to the principal you are a "representative" of your class, in the sense that you are bringing the opinions of the whole class with you.
