New Jersey Population Trends – North, South and Central 1840 – 2010

Map of North, South and Central New Jersey

The three regions of New Jersey as defined to develop the charts in this post

I’ve been pondering the differences between North Jersey, South Jersey and even Central Jersey for some time now. The more I look into the matter the more questions I have. It doesn’t seem enough just to identify regions and their differences but rather also to ask why the distinctions came to be.

In my last post, “Possibly the Split is East Jersey,West Jersey, not North Jersey, South Jersey“,I discussed the origins of two Jerseys — East and West — during Colonial times.  East Jersey related more to the Hudson River and New York, while West Jersey identified more with the Delaware River and Philadelphia. Transportation by water – especially the movement of goods – was essential to the development of the area. In the east, development thrived along the west bank of the Hudson River, Kill Van Kull and Arthur Kill. Camden, Trenton and Burlington grew along the east bank of the Delaware Bay (and River) from the Atlantic Ocean to the falls near Trenton where the river was not navigable. The population along the Atlantic shoreline was sparse due to the lack of safe harbors and anchorages for sailing vessels. It wasn’t until about the end of the first quarter of the 19th century that a maritime connection was made between the upper Delaware River and New York —  the Morris Canal. At about the same time, the Delaware and Raritan Canal opened providing a shortcut between New York and Trenton and Philadelphia.

Table for Statistics of Low Population Density Counties

Statistics for New Jersey Counties with a population density of less than 500 persons per square mile.

One of the distinctions often made between North Jersey and South Jersey is that “North Jersey is more crowded”. While that may be true of some of the North Jersey counties, it’s not true for all. Some of the Counties that I have described as belonging to North Jersey have population densities that are remarkably similar to other counties in the most southern part of the state. It seemed to me that Jersey population trends warranted some looking into. I started by reviewing the New Jersey County Statistics that I had gathered for my first post “Where am I — North Jersey, South Jersey, or Possibly Even Central Jersey?”  What I discovered was that some of the counties in North and Central Jersey had population densities as low or lower than those in the very southern portion of the state. The following table shows that seven counties have population densities of under 500 persons per square mile. So if the common wisdom “North Jersey is more densely populated than South Jersey” is not completely accurate, what else may we determine about New Jersey by the way its population has changed? What were the changes anyway?


Graph of New Jersey Population Changes by Region from 1790 - 2010

Graph of New Jersey Population Changes by Region from 1790 – 2010

Luckily, I didn’t need to tabulate all of the New Jersey population data myself. I first came upon New Jersey Population Trends 1790 – 2010 — a nifty excel spreadsheet created by none other than the NJ Department of Labor. From this data I was able to develop the graphs below, which portray the New Jersey population changes by region and the regional changes by county. The first graph shows that the North Jersey population grew earlier than that of either South Jersey or Central Jersey, who maintained similar growth patterns until about 1860 (although the Central Jersey population was slightly higher), when Central Jersey’s growth rate increased at pace that has exceeded South Jersey through the latest census. North Jersey expanded the most quickly beginning in the mid-19th century and continuing until about 1960 when its population dipped for approximately twenty years. The North still leads in population but Central Jersey continues to narrow the gap.


Graph of New Jersey Population Variations in North, South and Central Regions

Graph of New Jersey Population Variations in North, South and Central Regions

The second chart shows the regional trends in New Jersey population as a percentage of the total number of people living in the state. At the time of the first census the three regions claimed similar portions of the state’s residents – North and Central Jersey with approximately 35% and South Jersey with almost 30%.  Almost immediately, North Jersey’s population took off while the South and Central Jersey shares of the pie declined. The disparity reached its peak in the early part of the 20th century when Central Jersey began to close the population gap. South Jersey has not kept pace with the other regions and now contains only 20% of the New Jersey population. That, of course doesn’t tell the complete story — growth within the regions was far from uniform — creating a need in me to develop additional graphs.


The graphs that follow show changes in population by county from 1790 – 2010. I’ve grouped them by region in the hope that the display of information would be clearer. Please note that the county population data prior to the 1860 census is not completely accurate (sufficient, I believe, for this discussion), as it has not been adjusted for the following jurisdictional changes.

  •  Warren County was incorporated in November 1824, from portions of Sussex County.
  • Atlantic County was created in February 1837, from portions of Gloucester County.
  • Passaic County was created in February 1837, from portions of both Bergen County and Essex County.
  • Mercer County was founded February 1838, from portions of surrounding counties.
  • Hudson County was formed from Bergen in 1840.
  • Camden County was formed in March 1844, from portions of Gloucester County.
  • Ocean County was established in 1850 from portions of Monmouth County except for Little Egg Harbor Township which seceded from Burlington County in 1891.
  • Union County was formed in March 1857, from portions of Essex County.

I’ve left the evolution of the NJ County boundaries to be covered in a future post.


Graph of North Jersey Population 1790 - 2010 by County

Graph of North Jersey Population 1790 – 2010

The seven North Jersey counties all had small populations until about 1830 when Essex County’s growth rate began to rise more quickly than the rest. Hudson County took off in 1850, its development going stride for stride with Essex County until the turn of the 20th century when Essex surged ahead for good – late bloomer Bergen County surpassed Essex County in total population in 1980. Hudson County, whose growth potential was limited by being the smallest county in land area (47 sq. mi.), remains on top of the list for highest population density (13,495 persons per sq. mi) having a density more than twice than of Essex County. Passaic County has grown quite steadily from the mid 19th century to the present while Morris County’s growth spurt waited until after World War II. By contrast, Sussex and Warren Counties have experienced a much lower increase in population than the rest of North Jersey.


Graph of Central New Jersey Population 1790 - 2010 by County

Graph of Central New Jersey Population 1790 – 2010 by County

In Central Jersey, Midllesex, Mercer and Union Counties saw the earliest growth. Union County, part of Essex until 1857, took the lead in about 1900, to be surpassed by Middlesex County in about 1960. Monmouth County which had been in fourth place behind Mercer County moved up to third place in the early 1950’s and, in the 1970’s passed Union County for second place in Central Jersey. Ocean County’s growth started to skyrocket in the 1950’s bringing it into the third spot in 2010. As the largest county in area, Ocean still ranks in the bottom third of population density. Somerset and Hunterdon Counties have expanded at a more modest pace yet Somerset County has a population density similar to neighboring Morris County while Central Jersey’s Hunterdon County is as sparsely populated as Warren County in the North and Cumberland County far to the south.


Graph of South Jersey Population by County 1790-2010

Graph of South Jersey Population by County 1790-2010

In the early 1800’s Burlington County was the South Jersey population leader – not surpassed by Camden County until the 1870’s.  Today Camden County is the most populated of the South Jersey counties and has a density of almost twice that of runner-up GloucesterCounty.  Atlantic County was quite sparsely populated until the late 1800’s. It currently has a population similar to that of Gloucester County, which did not see significant growth until the 1950’s. The most Southern Jersey Counties – Salem, Cumberland and Cape May have not experienced the population growth of the rest of the South Jersey region. In fact, Salem County’s population density of 196 persons per square mile is less than 70% of that of Sussex County, the second most sparsely populated county in New Jersey.


Why did the counties of  the State of New Jersey develop at such different rates? What factors played a role in more rapid growth:

  • Transportation?
  • Sources of power for industry?
  • Proximity to New York and/or Philadelphia?
  • Natural and recreational resources?
In an upcoming post we’ll look at the development of one key municipality in each of the counties of New Jersey to see if we can find answers to some of these questions. I suspect that transportation resources in the form of ports, canals, railroads and highways will be the catalyst for growth in many regions while creating different patterns in each.
The author, Carl E. Peters is one of fewer than 10 people licensed by the State of New Jersey as a Professional Engineer, Professional Land Surveyor, Professional Planner, Construction Official, Building Subcode Official and Plumbing Subcode Official. He is also a Certified Municipal Engineer and Mediator and founder of Carl E. Peters, LLC