"Communities and state laws are now interpreting gender identity differently than society did in the past," Chief Scout Executive Michael Surbaugh said in a statement. "And these new laws vary widely from state to state."
In recent years the group has found itself embroiled in larger national debates about gender roles and sexual orientation. These debates, in turn, have led the Boy Scouts — which consists of about 2.3 million members — to examine long-held policies that date back to its founding days. In some instances, change has come swiftly. In others, it came only after years of legal battles.
Here are some pivotal moments in the Boy Scouts' transformation:
No women allowed?
The name speaks for itself: Boy Scouts of America.
The group, founded in 1910, was for boys and their male leaders, focused on promoting responsibility through an array of outdoor activities and educational opportunities.
Some boys came from single-parent households, and when their mothers volunteered to participate as Scoutmasters, they were rebuffed. Over the years, the group successfully defended the policy in court.
But in the 1980s, Catherine Pollard, a mother from Milford, Conn., sued the group to overturn the ban against women Scoutmasters, alleging it violated sex discrimination laws. The lengthy legal proceedings drew international attention, with attorneys for the Boy Scouts making a flurry of controversial comments during oral arguments.
"A Scoutmaster has gone through the biological changes taking place in boys," thus making him more qualified to be a Scoutmaster, attorney George Davidson argued on behalf of the Boy Scouts during a 1985 a hearing in Connecticut.
While the state Commission on Human Rights and Opportunities sided with Pollard, the courts did not. Ultimately, Pollard's case made it to the state Supreme Court in 1987, which upheld a lower-court ruling that sided with the Boy Scouts.
But Pollard's fight caught the public imagination, and in 1988, as the Boy Scouts faced mounting criticism from civil rights groups, the group's national executive board voted to allow women in leadership positions — including Scoutmaster.
Pollard became the first female Scoutmaster, and today, according to the Boy Scouts, nearly a third of the group's volunteers are women.
What about gays joining the Scouts?
From its founding, the group had a strict policy: No openly gay members.
"Boy Scouts of America," the group said, "believes that homosexual conduct is inconsistent with the obligations in the Scout Oath and Scout Law to be morally straight and clean in thought, word and deed."
The position reflected, in part, the sponsorship of Scout troops by churches. "A lot of churches played a significant role in the Boy Scouts," said Jay Mechling, a professor emeritus at UC Davis and an Eagle Scout who has written books about the group. "Churches still do play a role, but times have changed and views have changed."
In a 2016 Pew Research Center poll, 55% of Americans said they support same-sex marriage, compared with 37% who do not. (By contrast, a similar Pew poll in 2001 showed almost the opposite — 57% opposed same-sex marriage, compared with 35% in support.)
The advent of the
That same year, the Boy Scouts of America executive board began what would become a two-year review of its policy on gays. "It really was kind of a 'don't ask, don't tell' in the Boy Scouts. … It mirrored the military policy," Mechling said.
Some Scout leaders opposed lifting the ban, and the board voted to retain its policy.
But in 2013, as the group faced criticism from lesbian, gay, bisexual and transgender rights groups that assailed it as pushing discriminatory policies, the Boy Scouts formally announced an end to its ban on gay Scouts.
What about gay adult leaders?
Well, that remained in place. This created a conundrum: Once a gay boy turned 18, he would be barred from the group.
Such was the challenge facing Pascal Tessier. In 2014, Tessier, a 17-year-old from Maryland, became the first openly gay Eagle Scout. He wanted to continue to be associated with the group once he turned 18, but couldn't.
Enter former Defense Secretary Robert M. Gates, who became president of the Boy Scouts of America. Gates, who served under President Obama when "don't ask, don't tell" was repealed, urged the group to end its ban on gay leaders.
"I truly fear that any other alternative will be the end of us as a national movement," Gates said in a 2015 speech.
Eventually, the executive board sided with Gates and voted that year to end the policy on gay adult leaders.
The transgender debate
Rather than allowing any court battles or strong public pushback, the group this time looked to be preemptive as the debate over transgender rights continues to roar.
In North Carolina last year, lawmakers passed a bill that banned transgender people from using the bathrooms of the gender they identify with. And in Texas this year, Republican lawmakers have filed a similar bill that would require people to use the bathroom or locker room according to the gender on their birth certificates.
These laws continue to be castigated by the American Civil Liberties Union and LGBT rights groups, which call them discriminatory.
In December, the issue arrived before the Boy Scouts of America when an 8-year-old in New Jersey was asked to leave his Cub Scout troop after leaders and other parents found out he is transgender.
The group acted quickly.
"After weeks of significant conversations at all levels of our organization, we realized that referring to birth certificates as the reference point is no longer sufficient," said Surbaugh, the group's executive. He announced the new inclusive policy Jan. 30.
Zach Wahls, who cofounded Scouts for Equality, a nonprofit group that advocates for stronger protections in the organization for gay and transgender people, lauded the move.
"This is another historic day for the Boy Scouts of America. The decision to allow transgender boys to participate ... is an important step forward for this American institution," he said in a statement.