Reuters has issued a timeline of main events regarding LGBT rights in the United States:
1973: Maryland becomes the first state to ban gay marriage.
1977: Harvey Milk becomes first openly gay elected official in San Francisco.
1986: The Supreme Court says it's "unwilling to find a fundamental right to sodomy," even in the privacy of one's home (Bowers v. Hardwick).
1996: President Bill Clinton signs Defense of Marriage Act (DOMA), defining marriage as between a man and a woman for federal purposes, into law.
2000: Vermont becomes the first state to allow civil unions for same-sex couples, as Republican Vice Presidential candidate Dick Cheney, who has a lesbian daughter, indicates he supports gay marriage. "Freedom means freedom for everybody," he said.
2003: SCOTUS, via Justice Kennedy, strikes down Texas anti-sodomy law in Lawrence v. Texas.
2004: The Massachusetts Supreme Court rules in favor of same-sex marriage, and gay weddings.
2008: The California Supreme Court strikes down Prop 22, a 2000 state ban on gay marriage. Voters pass Prop 8, banning again same sex marriages in The Golden State.
2009: The Iowa Supreme Court legalizes same-sex marriage.
2011: The Obama administration ends the "don't ask don't tell policy," allowing gays to serve openly in the military.
2012: North Carolina approves a constitutional amendment to ban gay marriage, while Maine, Maryland and Washington become the first states where voters approve same-sex marriage. Also, President Barack Obama endorses same-sex marriage.
2013: The Supreme Court on March 26 and 27 hears oral arguments on the constitutionality of California's Prop 8 and the federal Defense of Marriage Act.