May 17 is on its way to becoming Marriage Equality Day.

It was on that day five years ago today that celebrations erupted in town halls across Massachusetts as the first gay and lesbian couples legally exchanged vows after the state Supreme Court ruled a gay marriage ban unconstitutional. The scenes were cheerful as hundreds of well wishers rushed to view history unfold before their eyes.

Since then, the state has issued thousands of marriage licenses to gay and lesbian couples.

In Provincetown, the gay mecca of New England, the legalization of gay marriage has created a booming gay wedding cottage industry.

But there have been rocky moments on the road to Marriage Equality Day. Years of hand wringing followed the court's decision as gay marriage foes fought to amend the state constitution to re-ban gay marriage. The Massachusetts constitutional amendment process may sound familiar to Iowans: Two consecutive wins in the Legislature, followed by a ballot measure. In 2007, lawmakers decided to leave well-enough alone.

And it wasn't until last summer that former Governor Mitt Romney's gay marriage moat was finally breached when lawmakers paved over an obscure 1913 law that banned non-residents from marrying in the state if the marriage was not recognized in their home state.

Last year, as Massachusetts approached its fourth anniversary, it stood alone in offering marriage equality, but since then five states have joined in the celebration. With the exception of Rhode Island, gay marriage is a reality throughout New England, and Iowa began issuing marriage licenses in April.

That's only about 5% of Americans, but that's up roughly 150% since last year. Add to the mix populous states currently leaning towards legalization – California, New York and New Jersey – and next year's total is certain to increase considerably.

The movement's rapid pace has left gay marriage opponents flatfooted, and scrambling for a new defense. In 2004, they decried judges who ruled against gay marriage bans, claiming they had usurped the authority of the Legislature. That argument crumbled for opponents this spring as three legislatures – and two governors – backed gay marriage. Pressed into a corner, gay marriage foes now say voters should be the ultimate arbiters of the issue. But a likely vote in Maine – a “people's veto” – this November is given a slim chance of success.

Coupled with new polling data that indicates a rapidly increasing acceptance for gay and lesbian rights and the writing is on the wall: Gay marriage has taken root in America.

In Massachusetts, a popular May 17 celebration is the Freedom to Marry ice cream social. This year, the dessert might taste a bit sweeter.