A federal law stated that a child born out of wedlock in a foreign country to an American father could become a United States citizen if, among other things, the father had lived continuously in the United States for 10 years prior to the child’s birth, at least five of which were after the father had turned 14. In contrast, the law provided that a child born out of wedlock in a foreign country to an American mother could become a United States citizen if, among other things, the mother had lived continuously in the United States for just one year prior to the child’s birth. Jose Morales lived in the United States until he moved to the Dominican Republic when he was 18. Morales thus did not live in the United States for five years after he turned 14. While living in the Dominican Republic, Morales had a son, Luis Ramon Morales-Santana (defendant). Morales-Santana moved to the United States when he was 13. Morales-Santana was convicted of several crimes, and the United States government (plaintiff) commenced deportation proceedings. Morales-Santana claimed that the citizenship law was unconstitutional because it unlawfully discriminated against men. The court of appeals found the statute to be unconstitutional. The United States Supreme Court granted certiorari.