Which case struck down the federal Defense of Marriage Act's recognition of same-sex marriages for federal purposes?

• A. United States v. Morrison (2000)
• B. United States v. Windsor (2013)
• C. Gitlow v. New York (1925)
• D. Barron v. Baltimore (1833)

Answer: (B)

The key idea is how federal law treats marriages that states have already defined. Defense of Marriage Act defined marriage for federal purposes as a union between one man and one woman, which meant same‑sex marriages recognized by states weren’t recognized for federal benefits. In Windsor v. United States (2013), the Supreme Court struck down that federal definition, holding it unconstitutional under the Fifth Amendment’s due process clause because it created a federal classification that denigrated and disadvantaged same‑sex couples in a way that state‑recognized marriages could not justify. The ruling makes clear that when a state approves a marriage, the federal government should respect that status for federal benefits, rather than impose a separate, unequal federal standard. This decision ended the federal government’s blanket denial of federal recognition to same‑sex marriages and set the stage for later nationwide recognition. The other listed cases address different constitutional issues—Morrison deals with violence against women and Congress’s power, while Gitlow and Barron concern incorporation and the reach of the Bill of Rights to the states—so they don’t speak to the federal recognition of same‑sex marriages.