Simplify the following text for a Grade 7 native English-speaking person.
Original: The 2000 census counted 7,448,618 , people living on Long Island , making it the most populated island in all of the United States , and more populated than Ireland and Jamaica .
Simplified: As of the 2000 census , Long Island had a population of 7,448,618 , making it the most populated island in any U.S. state or territory .