Gov. Tom Wolf signed into law last week a bill that sets 18 as the minimum age to obtain a marriage license.
Previously, those younger than 16 could get married if they had court approval, while those between the ages of 16 and 18 could get married with the consent of a parent or guardian.
"Setting the minimum age to obtain a marriage license will help prevent child exploitation," Wolf said in a news release. "Marriage is a sacred and serious commitment that should be undertaken with love by two adults, not by children being exploited by unscrupulous adults."
Though most states set the minimum marriage age at 18, exceptions in 47 states allow children under 18 to be married, according to Unchained At Last, an organization that advocates for an end to forced and child marriage.
Most states allow children ages 16 and 17 to marry if their parents provide consent.
"Obviously, one child's parental consent is another child's parental coercion, but state laws do not call for anyone to ask the children whether they are being pressured into marriage," Unchained At Last said on its website. "Even when a girl sobs openly while her parents sign the application and force her into marriage, the clerk has no authority to intervene."
In some states, a judge can approve a marriage for children under 16. Typically, such approvals are allowed when the child's age or the age difference between the couple "should trigger a statutory-rape charge," according to the organization.
About 248,000 children were married in the US between 2000 and 2010, according to an analysis by Unchained At Last. A majority of the children were young girls married to adult men. Some of the children were married at an age or had a spousal age difference that meant sexual relations between the couple would have legally constituted statutory rape, the organization said.