National New Jersey Day Date in the current year: July 27, 2025

New Jersey is a state located in the Northeastern and Mid-Atlantic regions of the United States. It is bordered by New York, Delaware, Pennsylvania, and the Atlantic Ocean. New Jersey is the fifth smallest state by land area, the eleventh most populous state, and the most densely populated state in the United States.

Before Europeans arrived in the region, the Lenape tribe dominated the area that is now New Jersey. The first European to explore the Jersey Shore was the Italian explorer Giovanni da Verrazzano, who was sailing in the service of France in 1524. However, he did not make contact with the local population. In the early 17th century, the Dutch East India Company explored the region.

The Dutch were the first to establish colonial settlements in present-day New Jersey. The area was part of the colony of New Netherland, which also encompassed present-day Connecticut, Delaware, New York, and a small portion of Pennsylvania. A portion of southwestern New Jersey was part of New Sweden until the Dutch conquered it in 1655.

In 1664, England conquered New Netherland and took control of the region. The part of the former Dutch colony west of the Hudson River was renamed New Jersey after the island of Jersey in the English Channel. That same year, King Charles II granted the region to his younger brother, the Duke of York (the future King James II), who then granted the land to John Berkeley, 1st Baron Berkeley of Stratton, and Sir George Carteret.

Ten years later, Berkeley sold his share of the Province of New Jersey to the Quakers, resulting in its division into East Jersey and West Jersey. In 1702, when Queen Anne ascended to the throne, East and West Jersey were reunited as a royal colony.

New Jersey was one of the Thirteen Colonies that declared independence from Great Britain in 1776. However, the colony still had many loyalists, and many slaves chose to fight for Britain in the Revolutionary War in exchange for freedom. Five major battles were fought in New Jersey during the war, earning it the nickname “Crossroads of the Revolution”: at Trenton, Princeton, Monmouth, Union, and Springfield.

In 1787, nearly four years after the war ended, the delegates drafted the Constitution of the United States at the Constitutional Convention. They then presented it to the states for ratification. Delaware was the first to ratify the Constitution, followed by Pennsylvania and New Jersey. New Jersey ratified the Constitution unanimously on December 18, 1787, becoming the third state to join the Union.

In 2017, National Day Calendar launched the National State Days project to celebrate the unique history, culture, and spirit of each state in the order that they joined the Union. The celebrations begin on July 13 with National Delaware Day, continue on July 20 with National Pennsylvania Day, and New Jersey’s turn to be celebrated comes on July 27.