Beth Robinson on Monday was sworn in as a member of the Vermont Supreme Court, making her the court's first openly gay justice.

Democratic Governor Peter Shumlin administered the oath to Robinson before a crowd of about 150.

Robinson, 46, a long-time gay rights advocate, led the legal team that successfully argued the groundbreaking 1999 Vermont Supreme Court case that led to the nation's first civil unions law. As the head of Vermont Freedom to Marry, Robinson lobbied lawmakers to approve a gay marriage bill two years ago.

“It was a different world just 12 years ago,” Shumlin said. “We've come a long way, most of it because of Beth's work.”

Robinson told the crowd that respect for the law was her highest priority.

“To me, my pledge is to remember the people because to me the only thing that is important is respecting this abstraction that we call the law, is respecting the people who both shape and give life to that abstraction and whose lives are, in turn, shaped by the dictates that the law requires,” Robinson said.

(Related: Barbara Lenk becomes first openly gay Massachusetts high court justice.)