"As an international citizen, (it) gives me so much gratitude because I see the very best that exists in this great nation," Witherington said. "... It's truly a beautiful thing."
Still, while he and other LGBT advocates characterized the court rulings as victories in their fight for equal rights, that doesn't mean the fight is over.
Some 70% of Americans live in the 37 states where same-sex marriage is not or will soon not be legal.
In his ruling opinion, Justice Anthony Kennedy said one reason the federal government is obliged to recognize gay and lesbian marriages that are legal in some places is because it is up to individual states to decide marriage law.
That's more likely to happen now than a few years ago, said Michael Cole-Schwartz, a spokesman for the Human Rights Campaign.
LGBT advocates have learned to make their campaigns more about people wanting to be together than people wanting to get rights and benefits, he said.
"We have really focused on the reasons why they want to get married: because they love each other," Cole-Schwarz said. "That's really helped change the nature of the conversation."
Workplace a battleground in LGBT fight
The Civil Rights Act makes it illegal for employers to discriminate against people based on their race, color, religion, sex or national origin.
But not their sexual identity.
That means, under federal law, there's nothing to prevent a worker from failing to hire or firing someone because they are gay or lesbian.
There are 21 states that do offer such protections, which leaves 29 that do not. In 34 states, there's nothing to prevent a person from getting fired if they are transgendered.
Activists are working to change that. Witherington points to the Employment Non-Discrimination Act working its way through a Senate committee, calling now a "crucial moment" for politicians to change federal policy.
The measure has 53 cosponsors, short of the 60 votes that bills typically need nowadays to pass if it's opposed by the Republican minority. If it does pass, it would then have to be passed in the GOP-led House of Representatives.
Selisse Berry, the founder and CEO of Out and Equal Workplace Advocates, says she's "very hopeful" a bill that includes protections for gay, lesbian, bisexual and transgendered people will pass. The larger movement in the society is a big reason why, she says.
"Any time people get to know us as human beings, it makes a huge difference," Berry said. "More and more people, all the time, are coming out. When that person has a relationship with others, it moves the dial forward."
Washington could take its cue from corporate America. On their own accord, most Fortune 500 companies already bar gays, lesbians and transgendered from being treated any differently than any other employee.
Why? Because they realize the importance of retaining the best people who perform well on the job, irrelevant of their sexual identity, according to Berry.
"It's about the bottom line, essentially," she says.
Activist: Gay rights' causes 'not insurmountable'