I have mentioned before that Robert Frost taught my grandfather 9th-grade English at Pinkerton Academy 1910-11. Gramps wasn't impressed, accurately assessing that Frost didn't much like teaching 9th-grade boys. One sees his point. His teacher left for England soon after, where he fell in with nature poets there who were called the Dymock poets. He had been writing poetry before this, and might well have been working on "Mending Wall" while teaching young Master Smith at PA. The analysis I linked to is simply the first one I half-liked while browsing them. I am not going to analyze it here, just use it as a jumping off spot for talking about libertarianism.
New England, especially Northern New England, has long been known for libertarianism - and yet also for much more public cooperation than other parts of the country, all the way back to colonial times. We built more churches, schools, roads, harbors, bridges, lighthouses, mills, meeting houses - and were willing to tax and demand labor from each other about this. I have usually described this as a devotion to the town (or very early, to the congregation), rather than any larger grouping such as even a county, but also not a valorisation of the individual. They were small-government, but not no-government people. It is ebbing away, but persisted for centuries, up until my own adulthood. You can still find it, but mostly only in comparison to the rest of the country at this point. I worked for the State of NH, and by the end of my career I had seen that bureaucracy grow in pointlessness and inefficiency.
Yet the Free Staters who came to NH have not always found the sympathy they expected here. Their choice of the porcupine as a symbol is revealing. It says "leave me alone," and I think that is what libertarianism means in most of the country. But here we think more along the lines of self-reliance, that is, your responsibility to take care of yourself and your own rather than the responsibility that others have to leave you alone. That's here too, and sometimes the "respect for privacy" can border on neglect of neighbors having trouble such as wives being beaten, or negative externalities from slaughterhouses being ignored. But it's not like we don't understand the premise of minding one's own business. It's just in second place rather than first more often up here than other libertarian places. The Upper South and the Empty Quarter would be the other main American examples.
What's different is the (ahem) unnoticed misplaced optimism of the rest of you, who seem to think that if we are just left alone, things will work out fine. They won't work out fine, no matter how many small-ball counterexamples you can find. When you build a City on a Hill it starts falling apart the next day, and requires effort, cooperative effort to keep up. This used to be admired, as in the early years of the American Republic other states actively looked to Massachusetts for how to self-govern, as their smaller places had never done this before. (My quick reading of what happened after is that slavery poisoned everything, even independence. It forced governance up to the county and then state level to protect propertied interests. We think of States Rights as small government and federalism now, but Goffstown didn't much hold with what Concord told them to do either, never mind Washington.)
Frost always said he was a bad farmer, but the evidence is otherwise. He was shrewd and hardworking and the financial records of his years at that task look pretty good. In "Mending Wall" we see the cooperative self-reliance at work. One doesn't need a lot of interaction and cooperation, but one does need some, and we can demand it of the other. Because... once the wall is built it's not going to stay built. It will need maintenance every year. It is interesting that Frost himself questions whether the job still needs to be done, now that no cows will invade the other property, but in the end he goes along, agreeing that somehow it does still need to be done, even if we can't quite see why.
Update: Yes, Massachusetts has largely gotten untracked on this after an excellent start of building an independent American economy and intellectual society so that we no longer had to look to London and Europe. The rich of all the regions sent their children to study in Europe, but Boston broke away before the Coastal South and even New York. It was a great idea, but perhaps they just got too full of themselves. SW Connecticut is not really part of New England anyway.