National Connecticut Day Date in the current year: August 10, 2025

Connecticut is a state in the Northeastern United States. Together with Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont, it makes up New England. Connecticut is bordered by Rhode Island, Massachusetts, and Long Island Sound. The state is named after the Connecticut River, which gets its name from the Algonquian word meaning “beside the long tidal river”.

Before Europeans arrived in the New World, many Native American tribes inhabited the territory that is now Connecticut, and some still reside in the area today. The first European to explore the region was the Dutch merchant and privateer Adriaen Block in 1614. Dutch fur traders built a fort near present-day Hartford, but they did not establish a colony.

The first English settlers arrived in the region in 1633. In 1635, John Winthrop the Younger established the Saybrook Colony at the mouth of the Connecticut River. In 1636, Thomas Hooker established the Connecticut Colony at Hartford. John Davenport and Theophilus Eaton founded the New Haven Colony in 1638.

Each English settlement in Connecticut operated as an independent political entity, lacking official sanction from the English Crown. In 1644, the Saybrook Colony merged with the Connecticut Colony. In 1662, Winthrop obtained a royal charter for the colony. Two years later, the smaller, less powerful New Haven Colony merged with the Connecticut Colony because it lacked a royal charter.

Connecticut was one of the original Thirteen Colonies that broke away from the British Crown during the American Revolution. Although no major battles were fought there, Connecticut played a significant role in the war by supplying troops, food, and war materials. Connecticut was also the launching site for a number of raids.

In May 1787, delegates from all thirteen colonies except Rhode Island convened in Philadelphia to discuss the federal government system. Originally called the Federal Convention or the Philadelphia Convention, the gathering became known as the Constitutional Convention because the delegates chose to write a new constitution instead of revising the Articles of Confederation.

Roger Sherman, one of Connecticut’s three representatives, became a key delegate at the convention by proposing the Connecticut Compromise. This compromise defined the bicameral structure of the U.S. legislature and won the approval of both more and less populous states.

The U.S. Constitution was signed by the delegates on September 17, 1787, and sent to the state legislatures for ratification. Connecticut became the fifth state to ratify the Constitution on January 9, 1788, with an almost unanimous vote.

National Connecticut Day is celebrated on August 10 as part of the National State Days project. Launched in 2017 by National Day Calendar, the project celebrates the rich history and culture of each state. Rather than marking the states’ admission anniversaries, National Day Calendar celebrates them in the order in which they joined the union, beginning with National Delaware Day on July 13.