NORTHAMPTON - Mount Holyoke College seniors Shannon Weber and Meredith Munn last month did what headstrong young people in love sometimes do: they eloped.

They did so not because their families weren't supportive (they were), but because they were worried their right to marry in the state they planned to move to after graduating from Mount Holyoke might evaporate.

It turned out they were right. And Saturday afternoon, the newlyweds were among an estimated 500 people who rallied on Main Street in Northampton, lending their voices to a chorus around the country protesting the passage of Proposition 8, a voter-approved initiative to repeal the judicial decision legalizing gay marriage in California.

For Munn and Weber, who said plans for graduate school will bring them back to Weber's home state of California, marrying there rather than Massachusetts, the first state in the country to legalize gay marriage, made more sense.

"Massachusetts marriage licenses don't mean anything there," said Munn, who is from Charlemont. As for the validity of their California marriage license, well, they're not sure.

"Nobody knows anything right now," said Weber. "Its new legal territory."

The couple, who are both 21, said the missed two days of classes when they flew to California to get married Oct. 28 (their professors at Mount Holyoke, they said, were very supportive.)

Weber was among the speakers at the rally Saturday, and she noted afterwards that it was good to be a part of a national action - the Northampton rally was one of hundreds held around the country to protest Proposition 8. She said since the election, it's been difficult to not be in California, where there have been large protests in most major cities.

"It's really good to see all across the country that people are able to make a difference today," she said.

Many of the rallies were largely organized via email and Face Book - and Weber said last time she checked Face Book, 661 people had RSVP'd their plans to attend the Northampton rally.

Munn said she figures the rain Saturday afternoon may have kept some people away.

There was a light drizzle for much of the 45 minute protest with rally-goers holding umbrellas and wearing raincoats. Rally-goers spilled off the sidewalk in front of the City Hall steps, where speakers and singers, and drummers address the crowd and led them in chants and songs. Police stationed orange traffic cones at the center of the street to route traffic away from the semi-circle of protesters that took up half of Main Street. Many cars passing by tooted and drivers waved.

Among the crowd were many people holding home-made signs with slogans such as "Equal not special," "No More Mrs. Nice Gay," "Separation of Church and Hate," "Et tu, California," and "Proud to be a Massachusetts American."

Easthampton resident David Sullivan, among the crowd, noted that Massachusetts is at the vanguard.

"There is going to have to be a movement to enshrine civil rights into the constitution," he said, "It's going to highlight how Massachusetts is a leader in civil rights."

Two hours after the rally had ended, a small group of people remained in front of city hall, holding signs and chanting "What do we want? Equal Rights. When do we want it? Yesterday."

Passing cars beeped their horns.