The Maryland Court of Appeals heard oral arguments on Monday in a case challenging a 1973 state law banning same-sex marriage. Plaintiffs, represented by the American Civil Liberties Union (ACLU), argued that marriage is a fundamental right which should not be denied according to the parties' genders. In response, Maryland Attorney General Robert Zarnoch argued that no court in the country has identified same-sex marriage as a fundamental right, and he urged the court to defer to the legislature. The state is appealing a January ruling by the Baltimore City Circuit Court in which the law was held to be discriminatory and unconstitutional.

Currently, Massachusetts is the only state to allow same-sex marriage, which was legalized when the Supreme Judicial Court of Massachusetts ruled in 2003 that a ban on such marriages was unconstitutional. Several cases similar to the Maryland case have been decided or are pending in other states including California, New Jersey, Washington, Tennessee, Nebraska, and Connecticut.