A national Coast Guard museum is years away from opening its doors along the city's downtown waterfront but it already has its first exhibit.

After the Coast Guard Museum Association announced its commitment to build an $80 million museum adjacent to City Pier, the New London Historical Society offered to loan its 13-star flag that dates back to the Revolutionary War to the exhibits.

"This is a national treasure that belongs in the national treasure we announced here today,'' Mayor Daryl Justin Finizio said at the announcement ceremony at the Science & Technology Magnet High School on April 5. Soon afterward, Finizio unveiled the framed flag, one of the last of its kind still in existence.

"We have our first exhibit. Now we just need a building to put it in,'' said Adm. Robert J. Papp Jr., commandant of the Coast Guard.

Edward Baker, executive director of the historical society, said the flag was restored, reframed and hung most recently at the Shaw Mansion for an exhibit that marked the 225th anniversary of the burning of New London.

The flag was first discovered in 1907 when the historical society purchased the Shaw Mansion to be its headquarters. The 13-star flag was discovered in the attic of the house, according to the historical society's website. At the time, Jane Perkins, who sold the house and was the great-great granddaughter of the original builder, Capt. Nathaniel Shaw, said the flag, dating to around 1777, belonged to the naval agent Nathaniel Shaw, who was Perkins' great-great uncle.

"It's a pretty rare thing,'' Baker said. "It's certainly a treasure for New London and will draw attention to other historical resources that are so close to this (Coast Guard) museum."

The flag is hand-stitched and made of silk ribbons sewn together for the stripes, according to the historical society. The stars on the field of blue are in a very unusual pattern - a circle of 10 with three in the middle.

Baker said he hopes the flag will draw people out of the museum, which will tell the history of the Coast Guard and its connection to New London, and into other historical sites throughout the city.

The National Coast Guard Museum, which officials expect to draw hundreds of thousands annually, will be a five-story, mostly glass structure, behind Union Station. It will be built above storm tide levels on pilings and will jut out over the Thames River like the bow of a ship and will tell the story of Coast Guard's past, present and future.

The building will have 26,000 square feet of exhibit space, 5,000 square feet of event space, a glass-roofed atrium and a gift shop, cafe and rooms for lectures and workshops.

In addition to the museum, a pedestrian walkway over the railroad tracks and a new terminal for high-speed ferry passengers for Cross Sound Ferry will also be built. The state has pledged $20 million for the walkway and other infrastructure improvements. Cross Sound officials said they will build the terminal, which will connect to the walkway and the museum, at a later date.

Gov. Dannel P. Malloy, who attended the announcement, said New London is a community that is on its way back. Finizio and U.S. Sen. Chris Murphy, D-Conn., both called the project transformational. U.S. Rep. Joe Courtney said the city has been waiting for a "magic ingredient" to capitalize on its many modes of transportation.

"It has the bones of a tourist destination because of its great history. Clearly having this blockbuster facility will make all of that come together,'' Murphy said.

The head of the museum association, James J. Coleman Jr., said he hopes the museum will open in three years. It will be free to visitors, he said, and he expects 800,000 visitors annually. He is counting on some of the estimated 500,000 people who take the ferry each year to stop into the museum.

The association will begin a national fundraising campaign immediately, Coleman said. He expects to raise millions from large donors and plans to ask for some federal funding.

The exhibit designer, Patrick Gallagher, president of Gallagher & Associates of Washington, D.C., has worked on dozens of museums including the International Spy Museum and the new National Army Museum.

The museum will include interactive exhibits, including a platform to measure how long it takes to get seasick and controls to simulate steering a ship. It will also have a rescue boat so people can feel what it's like to be strapped into a boat when it rolls over.

It was designed with a 9-year-old in mind, said Urs P. Gauchat, a dean at New Jersey's Science & Technology University, who is the architect.

"Whatever a 9-year-old likes, I like too,'' Gauchat said. "And if a 9-year-old likes it, they will come back again and again and again.''

K.EDGECOMB@THEDAY.COM