The legal landscape of same-sex marriage is ever-changing. As of July 2013, California, Connecticut, Delaware, the District of Columbia (D.C.), Iowa, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New York, Rhode Island, Vermont and Washington allow same-sex couples to get married and enjoy all of the benefits of marriage provided by the state.
Other states recognize marriage-like relationships that provide varying levels of benefits to same-sex couples. Domestic partnerships are available in Nevada and Oregan and will continue to be available in California, D.C., and Washington (for senior couples) even though these states also allow same-sex marriage. Colorado, Hawaii, Illinois and New Jersey provide civil unions. Wisconsin provides some limited statewide spousal rights to same-sex couples.
To learn more about same-sex relationship recognition in the United States, see Nolo's article, Same-Sex Marriage: Developments in the Law.