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Information released in August by the U.S. Census Bureau reports detailed information about where people were living as of April 1, 2020. It also has statistics on the racial/ethnic makeup of communities and housing numbers.

Many towns within Mercer County area saw moderate levels of population growth over the last 10 years, according to information released last month by the U.S. Census Bureau.

While some communities, such as Lawrence Township and Hopewell Borough, had small decreases in population, several towns, including Robbinsville, East Windsor and West Windsor grew faster than the county average over the last 10 years.

The statistics come from the 2020 Census Redistricting Data Summary File, and they provide the first look at detailed information about where people were living as of April 1, 2020. Numbers are available for the nation, states and communities down to the block level.

The report shows that people are increasingly living in cities and the surrounding areas. The population of U.S. metro areas grew by 9% from 2010 to 2020, resulting in 86% of the population living in U.S. metro areas in 2020, compared to 85% in 2010.

Mercer County

The population of Mercer County grew by 5.7% from 366,515 to 387,340—an increase of 20,825. This was a slower rate of growth than over the last 30 years. By comparison, the county grew by 35,000 residents from 2000-2010, and 25,499 from 1990-2000.

The numbers also show that the county became more diverse. The white population decreased by 20.7% from 225,012 to 178,447. That trend was also seen in most Mercer county municipalities.

There was a small .9% increase in the Black population from 74,320 to 74,993; and a 48.2% increase in the number of Asians from 32,752 to 48,537.

The Hispanic/Latino population was the other group that saw a large increase. That number went from 55,319 in 2010 to 84,177 in 2020, a 52.2% increase.

Other categories were: American Indian, from 1,194 to 2,442 (104.5%); Pacific Islander, from 295 to 206 (-30.2%); two or more races, from 10,087 to 33,143 (228.6%); and “other,” from 22,856 to 49,572 (6.2%).

The report also lists information on housing. The total number of housing units in Mercer increased by 7,273, from 143,169 to 150,442, an increase of 5.1%. Slightly more than 11,000 of those units are listed as being unoccupied.

The total population in group quarters in 2020 was 19,477, which includes 12,268 in college/university housing, 3,414 in adult correctional facilities and 1,632 in nursing homes. 

Census graphic

The Mercer County numbers are similar to those for the state of New Jersey, which also saw a population increase of 5.7% to 9.28 million people over the last decade.

The statistics for the towns in the communitynews.org coverage area appear below, in the order of magnitude of population increase.


Robbinsville Township grew at a rate that was more than double the county and state averages, with a population increase of 13.4%.

The population grew by 1,834 people—from 13,642 in 2010 to 15,476 in 2020. The number of housing units in Robbinsville went up by 410 from 5,277 to 5,687 (7.8%). There were 208 houses reported as being vacant.

In terms of cultural diversity, the total number of white people decreased 14.1% from 11,131 to 9,528. The percentage of white residents went from 81.6% in 2010 to 61.6% in 2020.

The second highest percentage is the Asian population, which went from 12.7% in 2010 to almost 30% in 2020. Overall, the Asian population increased 149%, from 1,729 to 4,312.

The number of Hispanic/Latino residents increased 40.1% from 564 to 790, and the number of Black residents went up 13.4% from 426 to 483.

The number of people identifying as being of two or more races increased 254.1 percent from 246 to 871.

West Windsor & Plainsboro

West Windsor Township was third in Mercer County in terms of population increase over the last decade. The population went up by 8.7%, from 27,165 to 29,518, an increase of 2,353 people.

The town saw an increase of 1,052 housing units from 9,810 to 10,862 (10.7%). A total of 493 units are listed as being vacant.

The report’s breakdown of population by race/ethnicity shows that there was a significant decrease in the number of white residents in West Windsor.

Overall, there was a decrease of almost 30% in the white population, from 14,924 in 2010 to 10,491 in 2020. The percentage of whites in the community went from 54% to 35.5%.

The majority population (52.6%) in town is Asian residents, which increased by 51.6%, from 10,245 to 15,527.

The number of Hispanic/Latino residents increased 24.2%, from 1,213 to 1,507. Other population increases included: Black people, 998 to 1,276 (27.9% increase); American Indian, 25 to 59 (136%); and those identifying themselves as having two or more ethnicities, 700 to 1,675 (139.3%).

Plainsboro Township, which shares a school district with West Windsor, but is located in Middlesex County, saw a more moderate increase in population—4.7%. The number of residents in town went from 22,999 to 24,084.

Plainsboro also saw a significant decrease in the white population, from 9,445 to 6,974 (26.2%). The number of Black residents living in town also decreased. That number went from 1,847 in 2010 to 1,646 in 2020, a 10.9% decrease.

Asians make up the majority of residents in town—56.5%. The number of Asians living in Plainsboro went from 10,630 to 13,596 (29.9%).

The Hispanic/Latino population saw only a small 1.4% increase, rising from 1,429 to 1,449—only 20 people. The number of residents identifying themselves as having two or more ethnicities went up 103.7%, from 600 to 1,222.

Very few housing units were built in Plainsboro over the last decade. According to the report, the number of units increase 1.9%, from 9,402 to 9,720. The Census Bureau reports that 561 were vacant.


Pennington's population increased from 2,585 to 2,802 (8.4%). The racial/ethnic breakdown shows that Pennington was one of the few towns in Mercer County that saw an increase in the number of white residents, going from 2,462 to 2,498 (1.5%).

There were large population increases in several categories, including: Hispanic/Latino, from 37 to 88 (137.8%); Asians, from 46 to 83 (80.4%); and those identifying as two or more races, from 37 to 88 (465.4%).

There was only a small number of homes built in town over the last decade. The number of residential units only increased from 1,083 to 1,088 (.5% ).


The numbers reported for Princeton were somewhat confusing, because Princeton Township and Princeton Borough consolidated into one community in 2013.

A number of print and online news outlets erroneously reported that Princeton was one of the fastest-growing towns in the state, not realizing that the 2010 number in the report (12,307) was for Princeton Borough only, and the 2020 number (30,681) is for the consolidated Princeton.

The Census report shows the municipality’s population growth as 149.3%. In actuality, in 2010, Princeton Township had 16,265, which added to the Borough’s population of 12,307 yields a total of 28,572.

That means the increase was really 2,100 residents (7.4%) for the consolidated Princeton.


The City of Trenton saw good growth over the last decade—from 84,913 to 90,871 (7%), a total of 5,913 residents. That’s a stark change from the previous decade, when the population decreased by 490 people from 2000-2010.

The largest growth was in the number of Hispanic/Latino residents, which went from 28,621 to 40,905, an increase of 42.9%. The biggest decrease in the city was in the number of white people, which went down by almost 46.8% from 22,549 to 12,004.

The number of Black residents decreased by 10%, from 44,160 to 39,703.


The population in Hamilton Township grew by 3,833 people since 2010, from 88,464 to 92,297. That’s a 4.3% increase.

Coincidentally, that number is also the percentage growth in housing in the township. The number of residential units went from 36,170 in 2010, to 37,716—an increase of 1,546 units—in 2020.

Hamilton saw a decrease in the number of white residents living in town—the from 69,340 to 57,798, a 16.6% decrease. Overall, white people still make up the majority, with 62.6% of the population.

The biggest population increase was in the number of people who fall into the category of two or more ethnicities. That population went up 344%, from 1,788 people in 2010 to 7,942 in 2020.

There was also a large increase in the number of Hispanic/Latino residents, which almost doubled, from 9,613 to 18,279, a 90.1% increase.

The number of Black residents in town increased by 17.1%, from 10,419 to 12,203, the number of Asians in Hamilton grew from 2,914 to 4,171 (43.1%), and American Indians increased from 149 to 427 (186.6%).


Ewing Township’s population grew by 4.1 percent over the last decade , from 35,790 to 37,264.

The racial/ethnic breakdown of the population change shows that the number of white residents decreased while all other categories went up. In 2010, whites were 63.1% of the population with 22,598 residents in town. By last year that number decreased to 18,280, which was 49.1% of the population. Overall, the white population decreased by 19.1%.

The second largest population in Ewing is Black residents at 31.4%. Overall that population increased 18.5% from 9,885 to 11,709.

The town also saw a 78.5% increase in Hispanic/Latino residents, from 2,727 to 4,868.

In other categories: the number of Asians increased by 27.1%, from 1,538 to 1,955; people identifying as two or more races increased by 207.8% from 842 to 2,592; and those in the “other” category, which increased by 217.6%, from 803 to 2,550.

The township saw a relatively large increase in housing units as compared to neighboring towns.

According to the Census Bureau report, the number of residential units went from 13,926 in 2010 to 15,637 in 2020—a 12.3% increase.

The report shows that 1,748 units are vacant. The majority of those are likely located in apartment complexes currently being constructed throughout the town.

Hopewell Township

While Hopewell Township didn’t see a decrease in population, it only grew by 1.1%. Over the past decade, the population increased from 17,304 to 17,491.

The report’s racial/ethnic breakdown shows that the community became more diverse. The white population decreased by 11%, from 15,010 to 13,357. One of the biggest increase was in the number of Asian residents, which went from 1,539 to 2,040 (32%). The number of Black residents was up by 69.5 percent. The town went from 364 in 2010 to 617 in 2020.

The Hispanic/Latino population in Hopewell Township increased by 81.3 percent, going from 573 to 1,039.

Another area that saw a large increase was the number of residents who identify as being of two or more ethnicities. That number went from 288 in 2010 to 1,164 in 2020, a 304.2% increase.

In terms of housing, Hopewell Township saw a 3% increase in the number of residential units. That number went from 6,551 in 2010 to 6,748 in 2020.

Hopewell Borough

Hopewell Borough saw a slight decrease in its population. The number of people living there went down by four people over the last decade, from 1,922 to 1,918 (-.2%).

A breakdown of the town’s racial and ethnic makeup shows a decrease in the white population in town, from 1,827 to 1,705—down 6.7%. Despite that, the percentage of white residents in town is 88.9 percent.

The number of Black people in the Borough increased by 10.3%, from 29 to 32, and the Asian population went up by 107.7 percent, from 13 to 27.

The number of Hispanic/Latino residents went up from 71 to 84, an 18.3% increase.

The Borough saw a small increase in the number of housing units—from 817 in 2010 to 828 in 2020 (1.3%). The Census Bureau reports 41 of those units as being vacant.


Lawrence Township saw the biggest population reduction in the county, going from 33,472 in 2010 to 33,077 in 2020—a decrease of 395 people (-1.2%).

According to the population/ethnicity statistics, the white population in town reduced by 4,431, from 22,322 to 18,891, a 19% decrease.

Increases included: Hispanic or Latino, 1,184 people, from 2,503 to 3,687 (47.3%); Asian, 11,171 people, from 4,721 to 5,892 (24.8%); Two or more, 1,640 people, from 819 to 2,450 (199.1%); Black, 295 people, from 3,602 to 3,897 (8.2%); and "Other," 945 people, from 913 to 1858 (103.5%).

In terms of residential housing, the community is essentially built out, which is borne out by the fact that Lawrence saw very few houses constructed over the last 10 years.

According to the Census Bureau report, there was an increase of only 29 housing units in town, from 13,239 to 13,268. A total of 718 of those units are identified as being vacant.

Lawrence Township Municipal Manager Kevin Nerwinski commented on the statistics.

“The very slight decline in population as shown in the 2020 U.S. Census suggests that the community maintains a consistent population level given that we are and have been essentially built out since the last census,” Nerwinski said. “The 2020 census was conducted during a world health pandemic and at a time when the political climate may have caused some from our diverse community to not participate.

“The importance of the census cannot be overestimated, and our community did an excellent job in getting the count that we did.”