Justice Kennedy pointed to some disturbing parts of US history in his gay rights opinion

The Supreme Court legalized gay marriage nationwide on Friday, and in his majority opinion Justice Anthony Kennedy acknowledged just how far gay rights have come in a short time.

From the opinion:

Until the mid-20th century, same-sex intimacy long had been condemned as immoral by the state itself in most Western nations, a belief often embodied in the criminal law. For this reason, among others, many persons did not deem homosexuals to have dignity in their own distinct identity.

A truthful declaration by same-sex couples of what was in their hearts had to remain unspoken. Even when a greater awareness of the humanity and integrity of homosexual persons came in the period after World War II, the argument that gays and lesbians had a just claim to dignity was in conflict with both law and widespread social conventions.

Same-sex intimacy remained a crime in many States. Gays and lesbians were prohibited from most government employment, barred from military service, excluded under immigration laws, targeted by police, and burdened in their right to associate.

For much of the 20th century, moreover, homosexuality was treated as an illness.

Kennedy illustrates an excellent point about how the status of gays in America has changed in a short time. Even in 1986, the Supreme Court upheld a Georgia law criminalizing anal sex between consenting adults. In 2003, Kennedy had the opportunity to reverse that decision when he wrote the majority opinion striking down the sodomy law in Texas.

Then in 2013, Kennedy wrote the majority opinion striking down the Defense of Marriage Act, a law which had held that the federal government couldn't recognize same-sex marriage.

In his opinion on Friday, Kennedy affirmed the equal status of gay Americans.

That opinion expressed why the right to gay marriage is so important.

"As the State itself makes marriage all the more precious by the significance it attaches to it, exclusion from that status has the effect of teaching that gays and lesbians are unequal in important respects," Kennedy wrote in his majority opinion.

He added, "It demeans gays and lesbians for the State to lock them out of a central institution of the nation's society."