U.S. postal inspector Anthony Comstock, whose eponymous law limited women’s access to contraception for a century, had a murky personal life. I spent years trying to flesh out his motives and psychology while researching my book The Man Who Hated Women: Sex, Censorship, and Civil Liberties in the Gilded Age.

His basic biography is well known: he was born in New Canaan, Connecticut, into a deeply religious Congregationalist family. His mother, Polly Lockwood Comstock, was a direct descendent of the Puritans, and died when he was 10. He thought all women should be in Polly’s mold—devoted to husband, family, and God.

Comstock served in the Civil War, and after moving to New York he befriended the scions at the Y.M.C.A., who helped him get to Washington in the 1870s and to get his law passed, which classified contraception as obscenity and criminalized its mailing.

He married Margaret Hamilton, the daughter of a clergyman, and they bought a house in Brooklyn. They had a baby, Lillie, who died in infancy. Several years later, they adopted a newborn who was said to have been found next to her mother’s corpse in Chinatown.

To get inside Comstock’s mind was difficult, as he left behind few personal writings.

When two Algonquin circle–era writers, Heywood Broun and Margaret Leech, published his biography in 1927, they had access to his diaries—spanning his Civil War service to the early years of marriage—which proved to be rich material, focused on his constant need to masturbate and his hatred of anyone who opposed him.

But the diaries have been lost for decades. Ralph Ginzburg, the 1960s-era publisher of Eros magazine, who was tried in the Supreme Court for obscenity and served an eight-month prison sentence, spent years working on a Comstock biography that he never published. In the course of his research he tried to find the Comstock diaries, to no avail.

When I set out to write a book about eight women prosecuted under the Comstock law, which banned both contraception and information about it sent by mail, I knew that their life stories would form the heart of my narrative.

Comstock thought all women should be in his mother’s mold—devoted to husband, family, and God.

Still, I wanted to fill in the life of Anthony Comstock. There were different theories as to the roots of his monomania about sex: his Congregationalist upbringing; the smutty postcards passed around by fellow soldiers during the war; his years as a young man in “sporting,” lascivious New York, where he roomed with brutes who chased prostitutes.

Broun and Leech speculated that a schoolteacher who punished him by insisting he wear a bonnet had turned him into a sadist. Some of Ginzburg’s papers posited that he was closeted.

There were different theories as to the roots of Comstock’s monomania, such as his years as a young man in “sporting,” lascivious New York, where he roomed with brutes who chased prostitutes.

I soon realized that a clue might lie in his mother’s death. She had been the most important figure in his life, the model of a Victorian woman. When he couldn’t find a job or was short on money or fell in love for the first time, he thought of Polly.

In an address at Clark University toward the end of his life, in 1909, Comstock said that when he was 10 years and 10 days old, he came home from school to find “the loveliest mother that ever lived, dead.” What had she died of?

At the New Canaan Museum & Historical Society, a one-minute walk from the very Congregational church where Comstock spent his Sundays growing up, I learned everything I could about “Smutty Tony,” including his childhood and family.

A genealogy book told me that the day Polly died, at the age of 37, was also the day Anthony’s younger sister Harriet was born. Harriet had been Polly’s eighth baby. And before Anthony’s birth, Polly had lost another baby, also named Harriet, in infancy.

I asked the librarian if they had anything else on Polly’s death. “We gave you all the materials,” she said. “For that you would have to go to Town Hall.”

A few minutes later I was there, looking through a records logbook as big as a pillow. I paged through to 1854, found March 17, and found Polly’s name. The cause of death: “Flooding.” A quick search on my phone told me that meant postpartum hemorrhaging.

The day Polly Comstock died, at the age of 37, was also the day Anthony’s younger sister Harriet was born. Harriet had been Polly’s eighth baby.

The realization that Comstock spent his life trying to squelch women’s reproductive control when his mother had died due to childbirth was jarring.

Had Polly Comstock had access to contraception, she might have had fewer children and survived to be at his wedding and meet his daughter Lillie. Would this have altered American history?

But certainly Polly would never have used contraception, even if she’d had access to it. She opposed all forms of contraception, viewing her husband as her master and believing it was God’s will that she give birth to many children.

That day in the town hall in New Canaan, I knew that my book would tell the life stories of the women who fought Comstock (including presidential candidate Victoria C. Woodhull and anarchist Emma Goldman), but it would also tell the story of the woman who gave birth to the man who hated women.

Maybe the most significant Comstock in American history was not Anthony but Polly. Her death, perversely, had strengthened his zeal—after the tragic loss, Anthony spent decades trying to force American women into unwanted pregnancies and childbirth, even if it led to their own deaths.

With the prospect of Roe v. Wade being overturned this fall when the court hears Dobbs v. Jackson Women’s Health Organization, millions of American women who have been denied abortion access may die young, too, due to botched or self-induced illegal abortions. Anthony’s and Polly’s ghosts are watching from wherever they are. They know that in 150 years little in this country has changed.

Amy Sohn’s The Man Who Hated Women: Sex, Censorship, and Civil Liberties in the Gilded Age is out now from Farrar, Straus and Giroux