Stonington — Danielle Chesebrough will leave the world of international diplomacy at the United Nations to take on tasks such as creating a town budget, finding more spots for people to park in downtown Mystic, building a park and protecting the town against rising sea levels.

On Tuesday, Chesebrough, an unaffiliated voter endorsed by the Democratic Town Committee, became the first-ever first selectwoman in the town’s long history, defeating Republican Selectman John Prue by a vote of 3,252 to 1,632. She will succeed Republican Rob Simmons, who chose not to seek re-election after two terms.

In addition, Democrat June Strunk and Republican Deborah Downie were elected as selectwomen, meaning the Board of Selectmen will comprise three women for the first time in the town's history.

Prue, Chesebrough and their supporters gathered, as is the tradition here, in the basement of Town Hall to hear the announcement of the official results.

When Chesebrough walked in, she and Prue shared a hug and a private conversation at the end of the hallway.

"Thanks for running a positive campaign," she told Prue.

Asked why she won and by a large margin, Chesebrough said her campaign energized unaffiliated voters and those wanting a positive campaign. She said the issues she talked about, such as coastal resiliency, resonated with voters.

"This is very humbling. I’m going to do the best job I can for the town," she said. "I’m grateful the Stonington Democratic Town Committee took a chance on me."

She also was congratulated by Simmons, who told her, "Good luck. Awesome. Very cool."

Prue was gracious in defeat, saying he disappointed his supporters. "I had hoped to do better. I thought it would be a close race, so I’m surprised," he said. "But the only person I can blame is myself."

Chesebrough, who takes office Nov. 18, works as senior analyst of investor relations for the United Nations’ Division of Corporate Sustainability and Responsible Investment; she now will leave that position. She also serves on the town’s Board of Finance and Economic Development Commission.

During the campaign, Chesebrough talked about beginning to implement the town’s coastal resiliency plan, continuing to work on the revitalization of downtown Pawcatuck, finding more parking in downtown Mystic, completing the Mystic River Boathouse Park project and installing sidewalks along busy Route 1 from the high school to downtown Pawcatuck.

j.wojtas@theday.com