The City That Boasts An Extensive History! Houston sprawls over 540 square miles of unique heritage and is the fourth largest city in the United States of America. Over 2 million people and 100 ethnic groups call the city home, spreading their culture and influence out in every direction. And one of the best ways to get around this vast city is by RV or Motorhome. You'll find a great deal right here to help the family budget go that much further.