Montpelier, Vt. ? Vermont was the first state to outlaw slavery. Neighboring New Hampshire declared its independence from England before any other colony. Maine led the way with Prohibition.

These days, Yankee activism has another cause — gay rights.

Two states in New England already allow same-sex marriage, and lawmakers in three more are considering it, although passage is far from certain.

To some, the push is emblematic of a live-and-let-live ethic and burnished by gradual acceptance of gay relationships after Vermont’s groundbreaking civil unions law took effect in 2000. Others see it as a targeted effort by a vocal minority that has turned to the Northeast because its message can’t get traction elsewhere.

Only Massachusetts and Connecticut permit same-sex marriage. California, which briefly allowed it before a voter initiative in November repealed it, allows domestic partnerships, as do a handful of other states.

New Jersey and New Hampshire also offer civil unions, which provide many of the same rights that come with marriage. New York recognizes same-sex marriages performed elsewhere, and legislators there and in New Jersey are weighing whether to offer marriage.

But for now, the focus on legal recognition of gay relationships has returned to northern New England.

“There is not an easy way to get the issue on the ballot and before the voters so that it can be decided directly by the people,” said Maggie Gallagher, president of the National Organization for Marriage, which opposes gay marriage and is underwriting a radio campaign against it.

“Therefore, it is more a creature of special interest politics and legislative dealmaking. These are small states which can be influenced by fairly large amounts of outside money coming in. And it’s very hard for regular people to feel that they can have a voice on this issue in these states.”

The voices — on both sides — are growing louder:

l New Hampshire, which enacted a civil unions law last year, moved a step closer to legalizing gay marriage Thursday when the state House of Representatives voted in favor. The state Senate still must vote, though, and the governor — who signed a civil unions bill last year — opposes it.

l The Vermont Senate has approved a similar measure, but the House has yet to vote. Gov. Jim Douglas vowed Wednesday to veto the bill if it reaches him, spurring a protest that drew about 300 people to the Statehouse on Friday. Protesters say they’ll push to get enough votes in the Legislature for a veto override.

l In Maine, a bill to legalize gay marriage has nearly 60 co-sponsors in the Legislature. Gov. John Baldacci, who opposes gay marriage, says he hasn’t taken a position on the measure.