The capital of NJ is Trenton, a city on the Delaware River in Mercer County. Trenton became New Jersey’s capital on November 25, 1790, and it is home to the New Jersey State House, the Governor’s office and the state Legislature. It is also the Mercer County seat, with 90,871 residents in the 2020 census. Trenton even served briefly as the capital of the United States, from November 1 to December 24, 1784.
Key Takeaways
- Trenton is the capital of New Jersey and has been since November 25, 1790.
- It sits in Mercer County on the Delaware River, across from Pennsylvania.
- Population: 90,871 in the 2020 census.
- It was briefly the U.S. capital in late 1784.
- The Battle of Trenton on December 26, 1776, was a turning point in the Revolutionary War.
- Before Trenton, New Jersey’s government met in Perth Amboy and Burlington.
Facts in this guide were checked in September 2026 against historical and census records.
Capital of NJ: Quick Facts
| Fact | Answer |
|---|---|
| State capital | Trenton |
| County | Mercer County (Trenton is the county seat) |
| Became state capital | November 25, 1790 |
| Population (2020 census) | 90,871 |
| River | Delaware River |
| Area code | 609 / 640 |
| Famous slogan | “Trenton Makes, The World Takes” |
| U.S. capital | November 1 to December 24, 1784 |
| Seat of government | New Jersey State House |
Why Is Trenton the Capital of NJ?
Before 1790, New Jersey did not have one permanent capital. During the colonial era, the province was split into East Jersey and West Jersey, and government business centered on Perth Amboy and Burlington. After independence, the Legislature moved between locations.
In 1790, lawmakers settled on Trenton, and the city formally became the capital on November 25, 1790. Its location on the Delaware River, between the state’s northern and southern halves, is often cited as a reason for the choice. Moreover, Trenton already had symbolic weight thanks to the Revolutionary War victory there in 1776.
A Short History of New Jersey’s Capital
| Year | Event |
|---|---|
| Colonial era | Government centered on Perth Amboy (East Jersey) and Burlington (West Jersey) |
| December 26, 1776 | George Washington crosses the Delaware and wins the Battle of Trenton |
| 1783 | Princeton hosts the Continental Congress at Nassau Hall |
| November 1 to December 24, 1784 | Trenton serves as the capital of the United States |
| November 25, 1790 | Trenton becomes New Jersey’s capital |
| 1792 | The original New Jersey State House is built |
| 1917 | “Trenton Makes, The World Takes” slogan adopted for the Lower Trenton Bridge |
The Battle of Trenton
On the night of December 25, 1776, George Washington led his army across the icy Delaware River. The next morning, December 26, his troops defeated Hessian soldiers stationed in Trenton. The victory lifted American morale at a critical point in the Revolutionary War.
When Trenton was the capital of the United States
Under the Articles of Confederation, Congress met in several cities. Trenton hosted Congress from November 1 to December 24, 1784, making it briefly the nation’s capital. Nearby Princeton had hosted Congress the year before, in 1783.
The New Jersey State House
The New Jersey State House in Trenton is the seat of state government. The original building dates to 1792, making it one of the oldest state capitol buildings in continuous use in the United States. It houses the Governor’s office and the chambers of the Senate and General Assembly. The building’s golden dome is a Trenton landmark, and public tours are offered, so check the Legislature’s schedule before visiting.
“Trenton Makes, The World Takes”
Trenton was once a major manufacturing center known for steel wire rope, ceramics and rubber goods. In 1917, the city adopted the slogan “Trenton Makes, The World Takes,” which still appears in large letters on the Lower Trenton Bridge over the Delaware River. The sign is one of the most photographed sights in the city.
Things to See in New Jersey’s Capital
- New Jersey State House: The historic seat of state government.
- Old Barracks Museum: A colonial-era barracks linked to the Battle of Trenton.
- Trenton Battle Monument: Marks the site where American artillery opened the battle.
- New Jersey State Museum: Exhibits on the state’s history, science and art.
- “Trenton Makes” bridge: The famous slogan over the Delaware River.
- Washington Crossing State Park: Nearby in Hopewell Township, where Washington’s troops landed in New Jersey.
Planning a Visit to the Capital of NJ
A visit to Trenton works well as a half-day or full-day trip. Many visitors combine the State House and museums downtown with a drive to Washington Crossing State Park, where the story of the famous river crossing continues. History fans can also continue north to Princeton, where Nassau Hall hosted Congress in 1783. Check opening days in advance, because museum and tour schedules vary, and some sites close on certain weekdays. Parking is available downtown, and the train station is a short ride or walk from the State House area. Weekdays are usually the best time for government building tours.
Getting to Trenton
Trenton is easy to reach by rail. The Trenton Transit Center is served by NJ Transit’s Northeast Corridor Line, Amtrak and SEPTA regional rail from Philadelphia, which makes the capital of NJ a convenient day trip from New York or Philadelphia. By car, Route 1, Route 29 and Interstate 295 all lead into the city.
Fun Facts About the Capital of NJ
- Two kinds of capital: Trenton has been both a state capital and, briefly, a national capital.
- River city: Trenton sits at the falls of the Delaware River, the head of navigation on the river.
- Revolutionary landmark: The Battle of Trenton is commemorated by the Trenton Battle Monument.
- Industrial past: The “Trenton Makes” slogan celebrates a manufacturing history that shaped the region.
- Neighboring capital region: Princeton, just north of Trenton in Mercer County, also hosted Congress in 1783.
How State Government Works in the Capital of NJ
Trenton is where New Jersey’s three branches of government are based. The Governor leads the executive branch from the State House. The Legislature has two chambers: a 40-member Senate and an 80-member General Assembly. Meanwhile, the New Jersey Supreme Court, the state’s highest court, also sits in Trenton.
| Branch | Institution | Based in Trenton? |
|---|---|---|
| Executive | Governor and state departments | Yes |
| Legislative | Senate (40 members) and General Assembly (80 members) | Yes, at the State House |
| Judicial | New Jersey Supreme Court | Yes |
Trenton Compared With New Jersey’s Largest Cities
| City | County | Role |
|---|---|---|
| Newark | Essex | Largest city in New Jersey |
| Jersey City | Hudson | Second-largest city |
| Paterson | Passaic | Third-largest city |
| Trenton | Mercer | State capital |
Common Questions About the Capital of NJ
Many people assume Newark or Jersey City is the capital because they are larger and better known. In fact, Newark is New Jersey’s largest city, while Trenton, a smaller city, serves as the capital. This pattern is common in the United States, where several states chose a more central city rather than their biggest one.
Whether you visit for history, government or a day trip, the capital of NJ rewards a few hours on foot. Start at the State House, walk to the Old Barracks and finish at the Battle Monument for a compact tour of Trenton’s story.
Explore More of New Jersey
Trenton uses the 609 and 640 area codes, which our guide to NJ area codes explains in full. To see which county every town belongs to, use our list of NJ towns by county. Looking for a day trip? Our guide to things to do in NJ includes nearby Princeton and Grounds For Sculpture. Find more in our Living in NJ section or on the homepage.
Frequently Asked Questions About the Capital of NJ
What is the capital of New Jersey?
Trenton is the capital of New Jersey. It sits on the Delaware River in Mercer County.
When did Trenton become the capital of NJ?
Trenton became New Jersey’s capital on November 25, 1790.
Was Trenton ever the capital of the United States?
Yes. Trenton served as the U.S. capital from November 1 to December 24, 1784.
What county is Trenton in?
Trenton is in Mercer County and is also the county seat.
What is the largest city in New Jersey?
Newark is New Jersey’s largest city. Trenton is smaller but serves as the state capital.
What were New Jersey’s capitals before Trenton?
Before 1790, government centered on Perth Amboy and Burlington, the historic capitals of East Jersey and West Jersey.
Where is the New Jersey State House?
The New Jersey State House is in Trenton, the capital of NJ, and houses the Governor’s office and the Legislature.
How many members does the New Jersey Legislature have?
The Legislature has 120 members: 40 in the Senate and 80 in the General Assembly.
Trenton at a Glance
The capital of NJ is Trenton, the Mercer County seat on the Delaware River. It became the capital in 1790, briefly served as the U.S. capital in 1784 and remains the home of the New Jersey State House. From the Battle of Trenton to the “Trenton Makes” bridge, the city packs a surprising amount of history into a compact downtown.
