"I think it was probably very much ... the typical American family, three boys growing up. We played baseball. We played in the neighborhood. We rode bikes. We pretty much did what other kids did in the '50s," said Bill Schroer.
Schroer's siblings never knew their little brother was suffering quietly, never daring to mention the anguish inside.
Schroer says growing up as a boy left her feeling uneasy and deeply conflicted about who she really was. "When I hit adolescence, it was, at times, consuming. ... So, I did everything I could to push that out of my mind," she told Roberts.
When David Schroer entered Northern Illinois University, he was in full denial of his gender crisis. He worked as an auto mechanic, an electrician and joined ROTC. After graduation, he entered Special Forces and somehow thrived in the most dangerous of military careers. He even fell in love with a woman and got married.
"We had a normal sexual relationship," Schroer said. "Although, I would say that I would often think of myself being on the other side of the relationship."
Schroer managed to keep up the act, rising through the ranks of the military. By his mid-40s, he was a Special Forces commander, leading a classified anti-terrorism unit and managing an $8 billion budget. He even briefed Vice President Dick Cheney on secret missions.
But he grew tired of denying what he believed was his true sexual identity.
"I think when I learned enough to understand what it was that I was really feeling ... I could either hide that, or I could acknowledge to the world that I was, in fact, a woman. And receive their acknowledgement back," Schroer told "20/20."
Schroer told his wife first, even hoping there might be a possibility they could stay together. But the couple decided to separate.
Schroer's marriage was over, but he found fulfillment for the first time. He began openly dressing as a woman and calling himself Diane. Schroer was retired at the time, and didn't have to break the news to Washington's top brass. But he began telling his Special Forces buddies, including retired Lt. Col. Dan Bernard.
"The way she explained it to me was by showing me some photos that had been taken of her as a woman in a business kind of setting, wearing makeup and with a big wig and women's clothes. ... And I didn't get mad and I didn't storm out," Bernard said.
"I explained to him about being transgendered and what that meant, and he sat back for a moment and said, 'You really had me scared. Wow, I thought you were going to tell me something bad.' ... It was a tremendous relief," Schroer recalled.
Now, Schroer was confident enough to tell family, nervously breaking the news to Bill and Gary -- still dressed as David.
Even though the news was, and continues to be, difficult to accept, Gary Schroer said there was never a question in his mind about being supportive to his younger brother. "It's still tough. But support and acceptance are two different things," he said.
Schroer then began the long and painful process of becoming a woman, undergoing intense therapy and taking female hormones under medical supervision. He also started wearing makeup, and underwent extensive cosmetic surgery.