Connecticut became the 5th state of the U.S:

 

As the Puritans from Massachusetts settled in Connecticut, 
it was then that it was officially founded. Leading up to the 1700s, as tension rose between America and England, a war began instigating due to the inclusion of taxing based on the Stamp Act and the Townshend Act, but Connecticut preferred independence, and as a result, they decided to adopt the declaration of independence in 1776.

Connecticut delegates were instrumental in bringing in the Great Compromise, also known as the Connecticut Compromise, at the United States Constitutional Convention in 1787. This was from big state delegates demanding that congressional representation be based on population, while smaller states demanded equal representation. The Connecticut Compromise established proportional representation in the House and equal representation in the Senate, allowing both large and small states to completely support a federal government, earning Connecticut the moniker "The Constitution State."
The articles of confederation were approved. After the armistice was declared, Connecticut worked side by side with other colonies, forming a new government, ratifying the new U.S. constitution in 1788,

It was then, Connecticut was officially known as the 5th state of the United States.