Ok, no that's simply not true. The US counts their cities populations differently than what Australians do. To crudly translate it, they count their local councils whereas Australia counts greater metropolitan areas.Garbage the New England Patriots are essentially Boston's team and Boston has a population of 700,000.
If Boston was in Australia it would be said to have a population of about 5 million people. If Melbourne was in the US it would be said to have a population of about 140,000.
Don't underestimate how big the US is.