Why is metro built elevated or underground?

So it won't interfere with street traffic. Parts of Seattle's metro are built at street level, and every time the train comes to one of those intersections, it closes the cross street until the train passes.

Read more

Why was the railroad important?

The U.S. Transcontinental Railroad was important because it joined the East Coast with the West Coast. It made it possible for thousands of people to immigrate to the West and settle the frontier. It made it possible to ship raw materials to factories in the East and products to communities in th...

Read more