Hillary Clinton, the presumptive Democratic presidential nominee, was among the thousands who participated in Sunday's New York City Pride Parade.

Clinton marched with New York City Mayor Bill de Blasio, New York Governor Andrew Cuomo and the Rev. Al Sharpton. Her appearance was unannounced.

The parade began with a moment of silence for the 49 people who died earlier this month in a mass shooting at a gay nightclub in Orlando. Forty-nine people also marched in the parade dressed in white holding images of those lost in the massacre.

Sunday also was the one year anniversary of the Supreme Court finding that gay and lesbian couples have a constitutional right to marry.

“One year ago, love triumphed in our highest court,” Clinton tweeted. “Yet LGBT Americans still face too many barriers. Let's keep marching until they don't. -H.”

She added in a statement on her website: “As we celebrate Pride – the hard-fought progress that generations of activists and advocates have made possible – we have to keep moving forward. We can't stop fighting until all Americans can live their lives free of prejudice and hate.”