CASCO BAY, Maine — The day-trippers wheel their bikes off the ferry and ask for directions. I answer the way we do on a island without street signs. Go up past the boatyard, beyond the store, and take your next left.

They thank me and head off. Then, at the last minute, one turns to offer me a cheerful salute: "Congratulations on your independence."

I've been fielding such good wishes from strangers and friends ever since the media outed the small island where my husband and I have had a summer home for more than 25 years. Nearly two weeks ago, Chebeague Island became the newest town in Maine, if not America.

If congratulations still sound odd to me, it's because in some ways we always thought of the island as independent. Surrounded by water that both separates and defines us, we had our own phone exchange and ZIP code, our own rescue and library and rec center.

When a car breaks down on Chebeague, there's no AAA to call. When an April storm knocks down trees and power, leaving the ill and elderly at risk, neighbors turn to each other.

But since 1821, we had in fact been a small part of the town of Cumberland. The seat of government had remained on the mainland.

Secession didn't come with some revolutionary's list of grievances, abuses, usurpations. Nor did the islanders complain about despots. The 350 year-round Chebeaguers did not have to pledge their sacred honor to each other or risk invasion.

What happened was a kind of continental drift. The suburb called Cumberland was heading one way. The island called Chebeague another. Then, two years ago, a letter arrived on the island announcing a plan to close the fourth and fifth grades of our school.

There are places in America where schoolchildren are increasingly seen as an expensive luxury or a tax burden. But here, everyone understood that the island's 20-plus schoolchildren were the difference between being a community and a summer resort.

So, what made fiscal sense to a suburb was lethal to an island. The desire to control our destiny took hold and grew into the plan for home rule.

When our 15 minutes of fame arrived, the media talked about our declaration of independence. But it was, in fact, more like a declaration of community.

It's a remarkable thing to watch a town being born. Self-government is labor intensive, I tell Herb Maine, a new selectman who lives in the oldest house on the island. He answers with a bemused shrug: "Life is labor intensive."

Some who opposed secession wanted to keep government "over there." What will happen, they worried, when problems can't be blamed on "them" and must be resolved by "us"? What will happen when neighbors make laws for neighbors?

Indeed many islanders spent long hours thinking about the balance of "trust and constraints" that go into self-governing. Herb Maine still wonders about the right proportions for a place where people leave their doors unlocked and feel sure that the volunteer rescue and firefighters will come as needed. "We hope to build a community on trust," he says, "not on rules and regulations."

Finally, on July 1, people proudly raised their green voting cards to approve a town meeting, a board of selectmen, a school board, an administrator. Sometime between dawn when the sun streaked out from the mist and evening when fireworks crackled over the bay, the newest experiment in the oldest democracy began.

On the mainland, the national political culture has become carelessly fractured. People who disagree go to the polar ends of their arguments and hurl opinions at each other. They live in cul-de-sacs of like-minded people as if they had no ground in common. How many Americans think of government as something imposed from Washington, not created at home?

I'm no island romantic. Chebeague is not Brigadoon, unless Brigadoon has WiFi. We have our share of feuds and a bell curve of political opinions. There will be times when arguments over taxes or zoning test our good will.

But I have lived here long enough to understand what it takes to maintain a community. I have seen it reinforced by every spring storm and family tribulation.

I'm one of the many summer folks who migrate here not to "get away" from it all, but to become part of it all.

Chebeaguers have long been stakeholders in the rocks, fields, forests and shorelines that stretch only two miles one way, five the other. At last, we have issued our Declaration of Community.

Chebeague is all ours now. Truly ours.

Ellen Goodman is a columnist for The Boston Globe. Reach her at ellengoodman@globe.com.