Last month, Delaware became the first state in the Union to ban child marriage. In all other states, legal exceptions allow minors—mostly girls, some as young as 12—to marry even if the state’s official minimum age is 18. Between 2000 and 2010, there were nearly 250,000 child marriages in the U.S., according to the nonprofit Unchained at Last.

Marriages between a girl under 18 and an adult man weren’t unusual in the early United States. In an era when most people didn’t know their exact birth date in the first place, most states went by British common law, which allowed girls to marry at 12 and boys at 14. But as perceptions of marriage and childhood shifted in the early 20th century, some Americans began to view marriages between teens and adults as strange or inappropriate. One turning point came in 1926 when a famous 51-year-old multimillionaire married a 15-year-old high school student.

New York real estate titan Edward Browning had already had a couple of public scandals by the time he met teenage Frances Belle Heenan. Newspapers had covered his divorce in 1923, when his first wife ran off to Europe with her married dentist. Edward and his first wife divorced in France and divided their two adopted children between them. But the bigger media scandal came afterward, when Edward took out newspaper ads saying he wanted to adopt a 14-year-old girl.

“This looks strange and fishy in the first place,” says Nicholas L. Syrett, a professor of Women, Gender and Sexuality Studies at the University of Kansas and author of American Child Bride: A History of Minors and Marriage in the United States. Edward claimed he only wanted a teen girl so his other adopted child could have a companion. Understandably, rumors circulated that that wasn’t the real reason.

“He ended up trying to adopt a girl who claimed to be 16,” Syrett says. “It then turned out she was actually 21 … The adoption fell apart because she was too old and because he had tried to pay the adoptive daughter’s parent—which was illegal in New York.”

Edward’s subsequent relationship with the 15-year-old Francis seemed to confirm suspicions around Edward. He met her at a high school dance for a sorority that she was pledging and he, creepily enough, was sponsoring. They only dated for a couple of months before marrying, and their wedding made the front page of the New York Times. Afterward, the media continued to report on the married life of Francis and Edward, referring to them as “Peaches” and “Daddy,” their pet names for each other.

Fifty years before, the Brownings’ marriage probably wouldn’t have been a big news story. Yet by the 1920s, shifting ideas about marriage and childhood had changed how people thought about unions between underage girls and adult men. For more than a century, Americans’ perception of marriage had been changing from a union that two people enter out of economic necessity to a more “complimentary” one that they enter because they’re in love. At the same time, Americans began to think of children as a class of people who needed special protections, like child labor laws, because they were different from adults.

In this context, a loving, fulfilling marriage between a child and an adult seemed strange at best, abusive at worse. The New York Society for the Prevention of Cruelty to Children tried to prevent the Brownings’ marriage by arguing that Edward and Francis’ mother were exploiting the 15 year old. Yet for many, the marriage wasn’t so much inappropriate as it was an amusing sideshow.

“They were among the most celebrated tabloid sensations of the 1920s,” Syrett says. “I think there were clearly people who thought that this was a problem and that he was going to try to take advantage of her, but there were also large numbers of people who saw her as a golddigger.”

Over the next several decades, news reports of child marriages began to draw more public outrage than the Brownings’ had. In 1937, news that a 22-year-old man in Tennessee had married a 9-year-old girl drew the kind of “How could this happen in America?” reactions that modern stories about child marriage do today. In 1958, the American music industry distanced itself from hit singer Jerry Lee Lewis when the public learned that the 22-year-old had married his 13-year-old cousin, Myra Gale Brown. Still, the scandal didn’t completely kill Lewis’ career, just as R. Kelly’s marriage to 15-year-old Aaliyah when he was 27 hasn’t ended his.

Until the mid-20th century, it was still fairly easy to get married illegally by faking parental consent, faking your age, or just driving to another state where the laws were different. During the 1950s, states tightened up the general age minimums and documentation needed for marriages, while at the same time adding legal exceptions that allowed teenage mothers of the baby boom to marry. “Pregnancy” and “parental consent” are two of the main exceptions that allow minors to marry in the U.S. In some states, there is no specified minimum age that these exceptions can apply to.

Multiple state legislatures and governors have rejected bills to set a hard minimum at 18. With Delaware’s precedent, activists hope that other states will become more receptive to banning child marriage completely.