Many people assume that a child born abroad who has a U.S. citizen parent is automatically a U.S. citizen. This is not the case. If only one parent is a U.S. citizen, that parent can't pass citizenship to a foreign-born child without specific criteria -- and the criteria have traditionally differed depending on the gender of the parent.

Since the Immigration and Naturalization Act was passed in 1952, it has been harder for a man to pass citizenship to his foreign-born child than for a woman. If a male U.S. citizen has a child prior to wedlock and that child is born abroad, he can only transmit his citizenship to the child if:

• He lived in the U.S. for 10 years before the child's birth
• For at least five of those years, he was over the age of 14

This may have been meant to address the fact that millions of young men having been abroad in the 1930s and 1940s during World War II -- most of whom would not have met these criteria.

A female U.S. citizen in the same situation can pass on her citizenship, however, as long as she has lived in the U.S. for a single year at any time during her life.

The government argues that the rules were meant to ensure that any foreign-born children claiming U.S. citizenship have a meaningful connection to a U.S.-citizen parent. If that's the justification, it doesn't make any sense, however, according to a recent decision by the U.S. Supreme Court.

"The scheme permits the transmission of citizenship to children who have no tie to the United States so long as their mother was a U. S. citizen" meeting minimal criteria, wrote Justice Ruth Bader Ginsburg for the unanimous court. New Justice Neil Gorsuch did not take part in the case.

"We hold that the gender line Congress drew is incompatible with the requirement that the government accord to all persons 'the equal protection of the laws.'"

Nevertheless, the court determined it did not have the power to rewrite the law; only to invalidate it in part. The sections in question are now invalid, but that does not confer citizenship on anyone. Immigration officials will now have to ensure the law is administered in a gender-neutral fashion until Congress rewrites the law.