Hillary Clinton marches in the NYC Pride Parade on Sunday. (Seth Wenig/AP)

Hillary Clinton made an unannounced appearance in the New York City Pride Parade on Sunday, marching alongside thousands of LGBT supporters two weeks after the massacre at an Orlando, Fla., gay nightclub.

The presumptive Democratic nominee joined New York City Mayor Bill de Blasio, New York Gov. Andrew Cuomo and the Rev. Al Sharpton at the event, which began with a moment of silence for the 49 shooting victims of the June 12 attack.

Clinton touted her appearance on social media:





Clinton has made appealing to the LGBT community a cornerstone of her presidential bid. On Friday, her campaign released a video featuring former Massachusetts Rep. Barney Frank highlighting her past experiences marching in the parade. Frank, who was the first openly gay member of Congress, described marching with Clinton in 2000 as “one of the most emotional moments of my life.”

In the clip, Frank noted that the country has made “great progress” on LGBT rights. However, he said, “we weren’t there in 2000.”

.@BarneyFrank on the time he marched in NYC's gay pride parade with the First Lady of the United States in 2000.https://t.co/G1b5cUV0pJ — Hillary Clinton (@HillaryClinton) June 25, 2016





Security was beefed up ahead of Sunday’s parade, with officials expecting the largest crowd in its history. And in light of the Orlando shooting, the New York City Police Department deployed extra security measures along the parade route.

Slideshow: New York dedicates Gay Pride to Orlando massacre victims >>>

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“New York police planned to deploy roving counterterrorism units and use bomb-sniffing dogs, rooftop observation posts, police helicopters and thousands of officers to provide extra layers of security at Sunday’s parade,” the Associated Press reported. “Thousands of uniformed officers were to line the route, supplemented by plainclothes officers in the crowd.”

A presidential candidate’s scheduled appearance at such an event would have undoubtedly complicated that plan. The Clinton campaign did not immediately respond to a request for comment from Yahoo News about her decision to march in the parade, but sources volunteering on her campaign said the team’s participation had been planned for multiple weeks and was a top priority.

Clinton, dressed in a blue pantsuit, was flanked by Secret Service as she waved to revelers in Greenwich Village near the historic Stonewall Inn, designated on Friday by President Obama as the first national monument to LGBT rights.

The Pride Parade comes nearly a year after the Supreme Court’s historic decision to legalize same-sex marriage. And the anniversary was not lost on the Democratic presidential hopeful.

One year ago, love triumphed in our highest court. Yet LGBT Americans still face too many barriers. Let's keep marching until they don't. -H — Hillary Clinton (@HillaryClinton) June 26, 2016





“One year ago, love triumphed in our highest court,” Clinton tweeted before joining the parade. “Yet LGBT Americans still face too many barriers. Let’s keep marching until they don’t.”

Later Sunday, Clinton is scheduled to speak at the U.S. Conference of Mayors in Indianapolis and then attend a finance event in Cincinnati.

— Additional reporting by Lisa Belkin