Hundreds of thousands of Americans took to streets from New York to San Francisco to celebrate gay pride, honor those who died in the Orlando massacre and promote tolerance.
San Francisco spectators faced metal detectors for the first time, and more police than usual were keeping watch.
Thousands of uniformed officers lined the route, supplemented by plainclothes officers in the crowd.
Security was ramped up at the events. New York police deployed roving counterterrorism units and used bomb-sniffing dogs, rooftop observation posts, police helicopters and thousands of officers to provide extra layers of security at Sunday's parade.
Many participants said the tributes to the dead in Orlando didn't dampen the energy and fun associated with the pride parade.
Despite the somber start, parade-goers seemed as enthusiastic as ever once marchers and floats began moving, cheering and dancing along the route.
In Chicago, 49 marchers at the head of the parade each held aloft a poster-sized photograph of a different Orlando victim as the procession wound through the city. Above each photo were the words, Never forget.'
An announcer introducing state officials and guests also shouted out, 'Love is love! New York is Orlando!' in memory of the 49 people killed in Florida.
Some spectators held up orange 'We are Orlando' signs, and indications of increased security were everywhere, with armed officers standing by.
Crowds of onlookers stood a dozen deep along Fifth Avenue for New York City's parade.
Rainbow flags were held high along with portraits of the dead as thousands of people marched in parades.