CHICAGO (NewsNation Now) —A new study shed light on a centuries-old issue still happening across the United States, child marriage.

The organization Unchained At Last found nearly 300,000 children under the age of 18 were legally married between 2000 and 2018.

“When I talk about this issue, invariably somebody says, ‘Child marriage is that a thing?’ Well it is and it’s a problem,” said Pennsylvania state representative Perry Warren.

The new study, funded by the Bill and Melinda Gates foundation, noted that the age or spousal difference is significant enough it would have been considered a sex crime for 60,000 of the cases.

“We don’t even let people take a drink until they’re 21 and we’re letting them get married at just 16. It just doesn’t make any sense,” said South Carolina state representative Brad Hutto.

Minnesota, Pennsylvania, New Jersey, and Delaware are the only states where 18 is the legal age to get married.

For other states, the legal age varies significantly.

The legal age is 17 in 10 states, while 21 others set the standard at 16. In Maryland, Hawaii and Kansas, it’s 15. North Carolina and Alaska allow them at 14.

Several states, such as California and Washington, don’t have a legal minimum age specified.

North Carolina just passed a bill to raise the legal age to 16 in their state Senate last week.

“I’m highly encouraged by the legislation that is being considered by a number of different states, particularly the bright line of 18, which would end child marriage in that state without exceptions,” said Kate Ryan, director of the documentary “Knots: A Forced Marriage Story.”

“The concept of marriage that I was going to get married, was a conversation we started to have right around the time I was maybe 11.” said one woman interviewed for the film.

Ryan shares stories of woman who were forced into marriage. She claims it’s been under-reported and unnoticed in the United States for decades.

“So it doesn’t matter whether you’re in a city, in a rural part of the country, in the suburbs, whatever religion you may practice, or a lot of secular communities as well, all kinds of ethnic, socioeconomic backgrounds,” said Ryan.

Ryan remarked child marriage is a diverse issue with lifelong consequences.

“Increased risk of domestic violence, poverty, lack of education, severe mental and physical health issues are also a huge issue with those who have experienced this kind of trauma,” she said.