But the U.S. government has dramatically reversed course. Over the past five years, it has spent nearly $1 billion to persuade young people that the only safe form of sex is within marriage -- and that condoms are not as effective as people think.
Hundreds of millions of dollars are being spent to bring the Abstinence-Only-Until-Marriage message to the nation's classrooms. Millions more are going to religious organizations that urge kids to take a virginity pledge promising to remain abstinent-until-marriage.
As first reported in May, it's a message many young Americans are eager to hear.
Amy Fritsche and Rick Gutierrez are high school sweethearts in Fort Myers, Fla. They're planning to do what more than two million young people have already done in the past 10 years: Take a pledge to remain virgins until marriage.
"You are not a virgin, right?" Bradley asks Rick.
"That's right, that's right… It's a second chance," says Rick.
"So you're OK with this? You don't mind?" asks Bradley. "Even though you've had sex before, you don't mind not having sex with your girlfriend?"
"I do not mind at all," says Rick. "I respect her greatly."
What do their friends who are sexually active think about Amy and Rick's decision?
"They think we can't do it," says Amy. "That it's impossible. But it's not."
Amy and Rick will be taking their virginity pledge at a music and light sex-education show called Silver Ring Thing. In the last few years, Silver Ring Thing has received more than $1 million in federal and state subsidies. Its aim is to encourage young people to put on a ring and promise to abstain from sex until marriage.
Denny Pattyn, a Christian youth minister, founded Silver Ring Thing in 1996. "After three-and-a-half hours of giving them our best shot [on stage], 75 percent become convinced and put on the ring," says Pattyn. "Our goal actually is to create a culture shift in America. We want to see the concept of abstinence be the norm rather than the exception."
Pattyn doesn't just preach the virtues of sexual abstinence. His show is full of negative messages about condoms – messages warning that condoms won't protect kids from pregnancy and sexually transmitted diseases.
"We spoke with some of the kids after the show in Fort Myers and they said that going into the program they thought that condoms did work, but your show convinced them that they didn't," says Bradley to Pattyn.
"Right. Well, that's good because we believe that condoms aren't the answer," says Pattyn.
"You're telling kids not to have sex. But some kids are going to have sex," says Bradley. "What do you tell those kids. You tell them not to wear a condom?"
"What I would say is: If you choose to use a condom, don't think you're getting the protection you think you're getting," says Pattyn.
"A kid's part of your program, and he comes to you and says, 'You know, I'm going to have sex. I've reached a point and I'm going to do this. Should I use a condom?' What do you say?" asks Bradley.
"My own daughter, my 16-year-old daughter, tells me she's going to be sexually active. I would not tell her to use a condom," says Pattyn. "I don't think it'll protect her. It won't protect her heart. It won't protect her emotional life. And it's not going to protect her. I don't want her to get out there and think that she's going to be protected using a condom."
But wouldn't his daughter be more protected with a condom than without? "Not long term," says Pattyn.
The federal government is spending $167 million this year to spread that abstinence-only message. And there's a law that says that for a program like Silver Ring Thing to receive government funding, it must not talk about the health benefits of using condoms -- only about how they fail.
Is this a good thing?
"It's a good thing because I've looked at the last 30 years. I've seen what the safe sex teaching has created both here and internationally," says Pattyn. "Thirty years and $5.4 billion later, of federal funds, look at what we have. We have a massive, massive mess sexually with teenagers."
Columbia University's Peter Bearman co-authored the most comprehensive study ever done on adolescent health and sexuality. He says, "Sex education doesn't cause all these negative outcomes. What causes these negative outcomes is kids who are having sex and aren't protecting themselves."
It was a $45-million project, funded by 17 separate federal agencies. Bearman's investigators interviewed more than 20,000 young people about virginity pledge programs -- and there was some good news.
"Pledging will help them delay sex for, say, 18 months — a year and a half," says Bearman. "It's a big deal in the lives of teenagers. Eighteen months is a phenomenally long time. It's almost two school years."
So what's the downside?
"The downside is that, when they have sex, pledgers are one-third less likely to use condoms at first sex," says Bearman. "So all of the benefit of the delay in terms of pregnancy-risk and in terms of STD acquisition -- poof -- it just disappears because they're so much less likely to use a condom at first sex."
Why do they not use condoms?
"They've been taught that condoms don't work; they're fearful of them. They don't know how to use them," says Bearman. "Their peers don't use them. They have no experience with them. They don't know how to get them. They're hard to get access to. For whatever reason they don't use them, that has long-term consequences."