Many in the crowd filling half of two blocks near the site of the proposed mosque held candles and waved American flags.
The controversy surrounding the mosque has vaulted it to a national stage, attracting Minnesota Congressman Keith Ellison.
"It's a bigger issue of belonging and inclusion," he said.
They come from across many races, religions and regions.
Lois Baker came from Wisconsin.
"God wants us to respect and honor and give all our fellow citizens dignity and grant them the same freedoms we want for ourselves," she said.
At least six other rallies are being planned on 9-11. Thousands are expected to gather near the World Trade Center site to rally both for and against the proposed mosque. Security will be tight during the September 11th ceremonies.
"I don't see any particular problems, but we're prepared for it," NYPD Commissioner Ray Kelly said.
Others wonder should this be happening on 9-11? Those supporting the Islamic community center claim they were forced to by those who will rally opposing the mosque.
"We absolutely had to respond. To remain silent in the face of a message of hate and conscious effort to whip up division in New York we could not allow," Sarah Flounders said.
Some 9-11 family members have called it insensitive to hold protests and rallies on a day of remembrance.
"My son is dead, he was murdered by Muslims. He can't speak anymore and i will keep speaking out for him and that's the American way. We'll let our voices be heard," Jim Riches said.
Friday night's vigil was sponsored by New York Neighbors for American Values, a coalition of 40 civic, religious and civil rights organizations.