Many people at the Sunday candlelight vigil for the Williamsville North High School freshman wore purple in solidarity with gay and anti-bullying causes, The Buffalo (N.Y.) News reported.
Rodemeyer's close friends and family spoke at the memorial event.
"I wish he had known that this many people cared about him before he left," his 16-year-old sister Alyssa said. "But it's up to us to make a change because of this."
Speakers used the "Paws Up" phrase from Lady Gaga's song "Born This Way." Rodemeyer, 14, was a huge fan of Gaga's music.
"He taught us that we should love everyone equally, and I know he is looking down on us from heaven right now, and his message is loud [and] is clear: A simple smile, a warm embrace or a friendly word can make a difference in someone's life," said his friend Stephen Spoth. "From this moment forward, we should make it our duty to continue Jamey's message of compassion to others."
A petition was circulated during the vigil calling for the school board to adopt an anti-bullying policy using input from students, parents, teachers, health care professionals and law enforcement officials.
In Buffalo, a smaller vigil for Rodemeyer was held later. Participants walked to Club Marcella with candles.
Speakers at the Buffalo vigil included Miguel Gorman of the Purple Door Project, gay marriage activist Kitty Lambert Rudd and state Sen. Mark J. Grisanti, R-Buffalo, who said, "I'm here because what happened to Jamey shouldn't happen to anybody. Enough is enough."