Among those who attended Monday's event was the family of Jamey Rodemeyer, 14, of New York, who committed suicide last September after being bullied for years. His suicide made national headlines and his family has fought ever since to prevent future suicides.
"One of the last things he said was 'Why doesn't anyone listen to how bullied I am?'" Jamey's mother, Tracy Rodemeyer, said. "Unfortunately, Jamey did not tell us or any other grown-ups that could have done something for him ... Bullying 20 years ago was an 8 to 3:30 event. You came home, got off the school bus, and that was it. But now it's 24/7. These kids are under attack."
The Monster March Against Bullying, organized by YouthVoice will be held in October and organizers are inviting gay-rights supporter Lady Gaga to join the festivities.
Following Jamey's death, Lady Gaga tweeted "Jamey Rodemeyer, 14 yrs old, took his life because of bullying. Bullying must become be illegal. It is a hate crime."
A petition to help get Lady Gaga to attend can be found at www.petitiononline.com/GaGaInv2/petition.html.
The group is also inviting President Obama, who has also been a supporter in the fight against bullying and was featured in a video as part of the 'It Gets Better' campaign.
Jonah Mowry, 14, of Lake Forest, Calif., has also been a victim of bullying and his YouTube video, "What's Goin On...", went viral with more than 9 million views.
"After my video came out, I realized that schools downplayed bullying and suicide as it was some sort of joke," Mowry said. "I used to cut myself all the time here and on my legs. I did it in secret but deep down I wanted someone to realize it was like a silent scream for help but no one could hear."
Since Mowry's video came out, his father, Kevin, said many of the comments posted on YouTube have been positive, but not all.
"The bullying continues today on YouTube on Jonah's video. And although the majority of comments are positive, there continue to be ugly, hateful comments," Kevin Mowry said. "Last week, there was a comment telling him if I ever see you I'd kill you and slit your throat -- and that written by a young teenage girl."
Jonah's father said he continues to delete negative comments on the video, leaving only the positive.
"Kids need to know bullying is so, so serious and it is nowhere near OK," Jonah said.
More than 160,000 students miss school because of bullying every year, according to YouthVoice and Monster March founder Christi O'Connor.
O'Connor said the group is expecting some 10,000 people to participate in the march in October.