Philip McAdoo and his partner, Sean Cavanaugh, were in the process of adopting their son, Zaden, while living in New York City before same-sex marriage was legalized there in 2011.
But by the time the official papers were finalized last year, they had moved to Georgia where laws prohibit gay marriage and adoption.
"During that whole period, we were being watched and observed before the adoption was finalized," said McAdoo, a 42-year-old doctoral student in education. "All that period we were considered a family, but only one of us was allowed to adopt him."
Zaden, now 8, was a foster child, in desperate need of a family.
Today, an estimated 399,546 children remain in foster care in the United States, according to 2012 statistics from the U.S. Administration for Children and Families. Of those, 101,719 are waiting to be adopted and 23,439 have "aged out" of the system.
"We wanted a black boy because they are considered the hardest to adopt and most at risk," McAdoo said.
In Georgia, where the couple moved because Cavanaugh works for the Atlanta-based Centers for Disease Control and Prevention, 7,669 children are in foster care and 1,645 of them are waiting for homes, according Allies for Adoption, a campaign to allow adoption by lesbian, bisexual, gay and transgender couples in all 50 states.
They say, too, that many potentially good parents are being overlooked. The majority of states do not allow adoption by same-sex couples.
"Right now there are children waiting to find a forever family, and until we knock down barriers to adoption by LGBT people in every state, we are failing them as a nation," said Gabriel Blau, executive director of the Family Equality Council."
Same-sex couples with children are four times more likely than their heterosexual couples to be raising an adopted child and six times more likely to be raising foster children, according to research from the Williams Institute, an LGBT think thank at UCLA.
Yet only 19 states and the District of Columbia permit same-sex couples to adopt jointly; only 13 states and D.C. allow second-parent adoptions; and only six states explicitly ban discrimination based on sexual orientation in foster care.
But Focus on the Family, a Christian ministry that is dedicated to helping parents raise children according to Biblical principles, said the push to legalize same-sex adoption has a "fundamental flaw."
"The ideal in the foster care system is to give children what they don't have -- a forever loving home with both a mother and a father," spokesman Paul Batura wrote in a statement to ABC News. "But by its very nature, same-sex parenting deprives a child of a mother or a father.
"We believe an adopted child has as much right as any other child to be raised in the environment most likely to promote, preserve and protect his or her emotional, psychological and physical well-being -- in other words, with a married mother and father."
In 2013, the Supreme Court dismantled the Defense of Marriage Act (DOMA), giving same-sex couples who are married the same federal rights as their heterosexual counterparts. But the states still have a patchwork of laws regarding marriage, adoption, taxes and inheritance laws.
Through a loophole in the law, McAdoo and Cavanaugh were allowed to adopt Zaden in a small Georgia county where one rotating judge interprets the law more liberally. But Zaden only has one parent on his birth certificate.
"We were flabbergasted," McAdoo said. "His birth certificate will follow him for the rest of his life and only one of us is acknowledged. I am on it, but my partner is not. ... I wonder what it will mean and what kind of hurdles there are."
According to a variety of studies, children raised in LGBT families fare as well as in hetersexual families.
"The research is unequivocal that lesbians and gays make good parents," said Adam Pertman, president of the Donaldson Adoption Institute and author of "Adoption Nation."
"It doesn't mean they do any more than straight parents, but when kids need homes, there is zero reason not to do this.