The document discusses 5 major cities in the United States - New York City, Los Angeles, Chicago, Houston, and Washington D.C. It provides key details about each city such as population size, location, notable districts or neighborhoods, and nicknames. New York is the most populous city with over 8 million residents and is known as "The Big Apple". Los Angeles has a population of around 3.8 million people and is home to the district of Hollywood. Chicago has over 2.7 million residents and has been home to influential politicians like Barack Obama.