The court cleared the way for same-sex marriages to resume in the state by leaving in place a trial court's declaration that the state's Proposition 8 ban was unconstitutional. In a 5-4 decision, justices decided Prop 8's backers had no legal standing in federal court.
The court also wiped away part of a federal anti-gay marriage law, the Defense of Marriage Act, which has kept legally married same-sex couples from receiving tax, health and pension benefits that are otherwise available to married couples.
Justice Anthony Kennedy, joined by the four liberal justices, said the purpose of the law was to impose a disadvantage and "a stigma upon all who enter into same-sex marriages made lawful by the unquestioned authority of the states."
What that should mean for all same-sex married couples is to celebrate today, and call your CPA tomorrow. Because on a practical level, the court ruling means same-sex married couples will now have to sort out all of the new federal benefits they're entitled to. And that, could be complicated.
"To the justices of the Supreme Court, thank you for affirming the principles of equal justice under the law," Edith Windsor said.
Windsor is the 84-year-old woman from New York who brought the case against DOMA. She sued to challenge a $363,000 federal estate tax bill after her partner of 44 years died in 2009.
Windsor, who goes by Edie, married Thea Spyer in 2007 after doctors told them Spyer would not live much longer. Spyer had suffered from multiple sclerosis for many years. She left everything she had to Windsor.
Windsor arrived at a news conference in New York after the ruling to applause from her supporters and said she felt "joyous, just joyous."
Windsor would have paid nothing in inheritance taxes if she had been married to a man. Now she is eligible for a refund.
President Obama called Windsor from Air Force One to congratulate her on Wednesday. He called the ruling a victory for all Americans.
Lynn Schuette and Tamora Horen live in Pacifica with their 13-year-old son Daniel. They've been a couple for two decades, but didn't get hitched, even though they had their chance to do it before Proposition 8 banned gay marriages.
When asked why they waited, they said it was because of taxes; adding that they'd had friends who had bad experiences with confusing tax filings.
"We found, from a number of our friends who did get married back then, that they had to file multiple tax returns because they had to file one way for the state and another way for the federal government," Schuette said.
Wednesday's ruling striking down DOMA now means Schuette and Horen will get married as soon as they can.
Steve Branton is a financial planner who has many same-sex married couples as clients.
"They'll be able to file jointly on their tax returns," he said. "They'll have access to social security benefits, you know, for their partner.
Also very important for Schuette and Horen -- they'll get a break from the federal estate tax. It's something that has concerned them since they have a son.
"As a parent, one of the anxieties I've always had was, if I get hit by a bus tomorrow, my partner and my son would all of a sudden be hit with a huge tax bill," Schuette said.
She and her partner can now plan their wedding. It's also something that their son has been waiting for.
"Most of my friends, you know, their parents are married," Daniel said. "I've always waited for the day to see my moms are married."
Now they can get married, knowing the government will treat them just like it treated their parents when they got married.
(The Associated Press contributed to this report)