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The historic change is set to occur next year. Cub Scout dens, or small groups of scouts, will remain single-gender, allowing for all-girls and all-boy groups.
Cub Scout packs, which are groups of dens, will have the option to incorporate girl groups into a pack, create an all-girl pack or remain all-boy packs, the group said in a statement.
A program allowing older girls to obtain the organization's highest rank, Eagle Scout, is expected to be announced next year and begin in 2019.
"The values of Scouting — trustworthy, loyal, helpful, kind, brave and reverent, for example — are important for both young men and women," Michael Surbaugh, the BSA’s Chief Scout Executive, said in a news release. "We believe it is critical to evolve how our programs meet the needs of families interested in positive and lifelong experiences for their children."
Girls are currently allowed to participate in four Boy Scouts programs — Venturing, Exploring, STEM and Sea Scouting — but had previously not been allowed to attain the rank of Eagle Scout.
The unanimous decision to allow girls came after meetings with various Boy Scouts groups, requests from member families with girls, and surveys of non-members with daughters expressing strong interest in Cub Scouts and Boy Scouts, the group said.
It also comes during a continued decline in membership for the Boy Scouts.
The BSA, which counts Secretary of State Rex Tillerson and former Secretary of Defense Robert Gates among its alumni, said it has 2.3 million youth members between the ages of 7 and 21, down from 2.6 million in 2013.
Allowing girls is the latest historic change for the organization, which announced in January that it would allow transgender children who identify as boys to enroll.
The decision to reach out to girls appeared to irk the Girl Scouts of America, which is a separate organization but has a similar mission.
Its president, Kathy Hopinkah Hannan, wrote a letter to the BSA president in August asking the organization to stop recruiting girls, according to The Associated Press.
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