How significant was the English colony at Guilford?

It is true that the colony of Guilford does not share in the significance of better known colonies such as Plymouth and Jamestown. However, Guilford should not be overlooked. It is representative of the hopes, struggles, and accomplishments of other colonies. It is also representative of the Puritan experience in the English colonies of New England.
When a group of Puritan colonists landed in what was to become Guilford in 1639, they brought with them the hopes of a community ready to practice their religion freely as Englishmen and Englishwomen in a land they felt was provided to them by divine providence. Nearby New Haven had been founded the previous year, but Guilford showed that the Puritans were ready to expand their presence throughout southern New England.
In Guildford, religious and secular matters were closely intertwined. This was typical of a Puritan settlement. The ministers were the settlement's community leaders and many laws, such as abstaining from work of Sundays and mandatory church attendance, showed the centrality of their faith.
Guilford also had atypically close relations with the local indigenous peoples. The colonists had purchased their land from the Menunkatuck who then helped in the construction of the settlement by querying and transporting stone (these same queries would be used over two centuries later to provide the material for the base of the Statue of Liberty). A healthy trade with the Menunkatucks continued for some time and some of them even came to reside in Guilford itself.
All in all, Guilford's history and achievements did not elevate it to the same station as New Haven, some fifteen miles to the west. It never had the same population as the larger English settlements in New England. However, it serves as a great example of a small colony that grew steadily and became influential locally. Throughout its colonial history, Guilford stayed true to its founding ideals of liberty and self-sufficiency.
http://www.visitguilfordct.com/colonial-life-in-guilford/

https://connecticuthistory.org/towns-page/guilford/