An appeals court has ruled that a law that denies a host of federal benefits to same-sex married couples is unconstitutional. The 1st U.S. Circuit Court of Appeals in Boston ruled Thursday that the Defense of Marriage Act, which defines marriage as a union between a man and a woman, discriminates against gay couples. The law was passed in 1996 at a time when it appeared Hawaii would legalize gay marriage. Since then, many states have instituted their own bans on gay marriage, while eight states have approved it, led by Massachusetts in 2004. In 2010, a federal judge in Massachusetts declared the heart of the law unconstitutional in two separate lawsuits. The judge found that the law interferes with the right of a state to define marriage.