WATCH: President Obama Calls Marriage Equality Ruling 'A Victory for America'

All Americans are proud to live in this country today, especially the President.

President Barack Obama declared Friday that the Supreme Court ruling legazling same-sex marriage "is a victory for America."

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From the White House Rose Garden, President Obama said that the social progress sometimes comes in small steps, "and then there are days like this, when that slow, steady effort is rewarded with justice that arrives like a thunderbolt."

In the landmark decision, the court ruled 5-4 that same-sex couples have a constitutional right to marry. Justice Anthony Kennedy, delivering the majority opinion, wrote that same-sex couples should "not to be condemned to live in loneliness, excluded from one of civilization's oldest institutions. They ask for equal dignity in the eyes of the law. The Constitution grants them that right."

The lead plantiff in the case, James Obergefell of Ohio, was being interviewed on CNN when the President called to congratulate him.

"Your leadership on this changed the country," Obama told Obergefell, when he took the President's call live on the air.

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President Obama endorsed same sex-marriage back in May of 2012. On Friday, he noted the swift progress towards marriage equality in the United States.

"An entire country realized that love is love," he said. "What an extraordinary achievement, but what a vindication of the belief that ordinary people can do extraordinary things."

Watch President Obama's full reaction below: