At the 2010 United States Census, there were 1,585,873 people living in Manhattan, an increase of 3.2% since 2000. Since 2010, Manhattans population was estimated by the Census Bureau to have increased 5.0% to 1,664,727 , representing 19.3% of New York Citys population of 8,622,698 and 8.4% of New York States population of 19,849,399. As of the 2017 Census estimates, the population density of New York County was around 72,918 people per square mile (28,154/km²), the highest population density of any county in the United States. In 1910, at the height of European immigration to New York, Manhattans population density reached a peak of 101,548 people per square mile (39,208/km²).. Which year had a higher population living in Manhattan, 2000 or 2010?