Supporters of the gun bill are hoping to seize momentum on the issue with the U.S. Senate scheduled to begin debate on Tuesday.
The event was held as the United States Senate prepares to debate the most significant gun control bill in nearly two decades, which calls for expanded background checks on many gun purchases, tougher penalties for those who buy guns for others and a record-keeping system to track guns used in crimes.
"It's not about taking away second amendment rights. It's about protecting innocent people," said Rev. Wendy Witt, First United Methodist Church.
But opponents of the bill Say it's heavy-handed.
"With a national registry of firearms comes potential for abuse by officials. And none of it would have any effect on the kind of high profile crimes that have been in the news lately," said Mike Weisman, Illinois State Rifle Association.
The fight for new gun laws appeared lost earlier this month before an intense lobbying effort by some parents of Newtown, Conn. shooting victims.
The President's usual Saturday web address was instead delivered by Francine Wheeler, who lost her son at Sandy Hook Elementary.
"Our younger son Ben, age 6, was murdered in his first grade classroom on December 14th, exactly four months ago this weekend," Wheeler said. "Please help us do something before our tragedy becomes your tragedy."
Organizers of Sunday night's vigil say they plan to set up a phone bank next week to pressure lawmakers on the issue. Among those on their call list is Illinois Senator Mark Kirk.