All the talk this year of the Girl Scouts’ 100th anniversary stirred a memory in Sarah Redpath. Back in 1978, she recalled, her parents had loaded an ancient Girl Scouts uniform into a car and driven it to the Smithsonian Institute in Washington D.C.

The tan blouse-and-skirt ensemble belonged to Ruth Colby Donan, Redpath’s grandmother and a charter member of the Girl Scouts, Redpath said. And when Redpath inquired about the fate of the old uniform, she heard something surprising: The National Museum of American History was going to put the vintage outfit into its Girl Scouts centennial display.

Neither the museum nor the family is sure exactly how old Donan’s uniform is. It appears to be an early scout leader’s uniform, dotted with sewn patches, including a honeybee, a flower and a bonnet.

Family history says Donan was one of the Scouts’ first generations. The organization was founded in 1912, and the uniform could be from 1917 to 1919, Smithsonian staff told Redpath, based on its styling.

Redpath and her family of five – including Girl Scout Clarissa Redpath – recently set off by train to see the relic themselves. When they arrived, they were treated to a personal tour, including a look at the Museum of American History’s storage rooms.

They also shared the family story with Timothy Winkle, a museum curator, so that he could narrow down the possible age and origin of the uniform.

“We continue to look for clues to help the Smithsonian date it more exactly,” Redpath wrote in an email. “It’s been a lot of fun, and we’ve learned many things about Clarissa’s great-grandmother previously unknown.”

The uniform required some special research, especially because it featured rare examples of the Scouts’ early non-standardized patches.

Redpath believes her grandmother may have come to the Girl Scouts through Troop 4, a Montclair, N.J., group that was among the first of the Boy Scouts.

“Certainly Ruth was at least associated with some of the pioneers in the early days of scouting,” Redpath wrote, “and maybe even (Girl Scouts founder) Juliette Low herself.”