Discover why New York City is the most populous U.S. city, boasting over 8.3 million residents across its five boroughs.

A heat dome​ is trapping over 90 million Americans in extreme temperatures this week with the National Weather Service​ ...

Why It Matters. Amtrak is the largest high-speed rail provider in the United States, carrying over 30 million passengers annually. It is supported by state and federal subsidies, much of which is ...