The concept of the pill—as in “the pill,” as in the oral contraceptive that’s a routine part of daily life for millions of women around the world—sounds like science fiction when you reduce it to its most elemental. Everyday you swallow a tiny pill, and your body suspends its ability to procreate.

Through most of the first half of the 20th century, women’s rights activist Margaret Sanger looked to science to develop such a mythic means of birth control, and she found no takers. A pill that prevented pregnancy seemed a ridiculous proposition—too risky, too dangerous, too much a challenge to the natural order.

Still, Sanger looked. And she eventually found Dr. Gregory Pincus, a Harvard scientist who was developing an early form of in vitro fertilization. And she found Katharine McCormick, a wealthy woman who could underwrite the research. And Pincus found Dr. John Rock, a dashing gynecologist who helped him develop and test what came to be a safe, effective, and widely used oral contraceptive.

Former Wall Street Journal reporter Jonathan Eig tells the story of how Sanger’s persistence, Pincus’ ingenuity, McCormick’s support and Rock’s acumen led to its development in The Birth of the Pill: How Four Crusaders Reinvented Sex and Launched a Revolution.

In an interview with Kirkus Reviews, Eig talks about the social backdrop of the early 1950s, the challenges of developing such a radical method of birth control, and the four principal characters he found while researching the book.

Are you expecting this book to resonate with current birth-control politics?

I definitely hope that it will resonate with people. We’re still fighting over birth control. I went out of my way in this book not to hit people over the head with politics. My goal all along was to give people a chance to reflect on how we got to where we are today, and our relationship with birth control, and where it began, and how the pill changed the culture. We take for granted now that women can decide whether to have babies, and that wasn’t always the case.

The oral contraceptive in use today is basically the same as what Dr. Pincus developed in the 1950s, right?

That’s absolutely right. Pincus had the idea that if he could trick the body into thinking it was pregnant, it wouldn’t get pregnant. The woman would not release the egg and the egg would not implant because the body would think it had already begun a pregnancy.

And it went into extremely wide use fairly soon after the FDA approved it?

It captured an audience quickly. Even before it was approved, women had begun to ask their doctors about it.

Why did you stop the book with the development of the pill and not go into the culture change once the pill became available?

I wanted the book to be about invention—how we got the pill—and once the pill is unleashed, that’s a different book. That’s more of a sociology book, and I wanted to write a history of how we got the pill. Once the genie’s out of the bottle, that felt like a very different story to me.

Margaret Sanger had been a lifelong advocate for birth control, and she was in her ‘70s or ‘80s, I think, when she approached Dr. Pincus. What took her so long?

She had this idea for 30 or 40 years that there ought to be a pill. After World War II, people started to understand hormones a lot better, and it dawned on her that maybe hormone science might work. She looked for decades to sponsor some research; she just couldn’t find anybody. People were not interested because it would be bad for their careers, or they thought it would be a waste of time because they could never get approval for such a drug. It was a great fortune that she ran into Pincus and found a scientist willing to take that chance.

There is an antipathy toward birth control among some conservatives today that seems to go beyond longstanding Catholic orthodoxy. Where do you think that comes from?

A lot of it comes from sexism. We don’t mind when the government pays for drugs for men that helps them have sex. Viagra is covered by most insurance plans. Many of the people in charge don’t like the idea of giving women “permission” to have sex, and they’re not comfortable with women making choices about their own bodies.

Where do you see conservatives pressing on contraception as an issue?

When the pill first came along, a lot of people in the Catholic church—including the Pope—were open-minded about it. A lot of Republicans in the 1950s and ‘60s embraced birth control as an important development for women. It was really in the ‘80s and ‘90s when you started to see this backlash that the Republicans decided this was an issue they could use. It wasn’t always political.

Pincus had no university or federal funding and did not work directly for a drug manufacturer. Was that a typical setup for drug research in the 1950s?

There was really nothing typical about what Pincus and Sanger did. They basically operated as renegades because they could not get university funding for this work—and they had a hard time getting corporate funding until the end—because it was seen as so controversial. Birth control was illegal in 30 states when they began their research; what they were doing was dangerous. They got most of their funding from Katherine McCormick. If it weren’t from her checkbook, I don’t think we would ever have developed the pill.

Contraception being illegal sounds so completely foreign today. Why was it ever illegal?

It goes all the way back to the Comstock laws after the Civil War where we thought pornography and sex were out of control. A great wave of Puritanism swept the country, and those laws were still on the books in many states in the 1950s.

Condoms were widely used by the 1950s, so it’s not like birth control of any kind was taboo. Why was the pill such a threat?

Men controlled it, and women often had little say in the matter. The important thing for Sanger was coming up with something that women would be able to access and employ without the permission of men.

Pincus didn’t strike me as trying to make money on the development of the pill. Did you see anything to the contrary?

Not at all. He certainly could have made more money from it than he did. There were moments when he faced the choice of holding out for money and getting the pill approved as soon as possible, and he always chose getting the pill into women’s hands and worrying about the money later. He never made a lot of money from the pill.

Why wasn’t the pill perceived by conservatives as a mechanism for reducing abortion?

You could ask the same question today. If you provide people with better contraception, you will have fewer abortions. Something like 60 percent of all pregnancies are unintended and half of them end in abortion. If you’re opposed to abortion, you ought to be in favor of better birth control.

Scott Porch is an attorney and contributing writer for Kirkus Reviews and The Daily Beast. He is writing a book about social upheaval in the 1960s and '70s.