Key Facts– A US statute determining whether or not the child of one US citizen parent and one non-US citizen parent was a US citizen imposed different requirements depending upon whether the mother or father was a US citizen.
Issue– Does this violate Equal Protection?
Result– Law affirmed
Reasoning– It’s easy to be certain of who a child’s mother is. It is much more difficult to be certain of paternity, especially when the parents are unmarried. From a practical biological standpoint, there are very real reasons for a legal difference in treatment.