A Connecticut town held a moment of silence Friday for the victims of an elementary school massacre at a remembrance event that doubled as a call to action on gun control, with the reading of names of thousands of victims of gun violence.

Two sisters of slain teacher Victoria Soto asked the crowd gathered at a town hall in Newtown for a 26-second moment of silence, honoring the 20 children and six adults gunned down at Sandy Hook Elementary school on Dec. 14.

The event then transitioned to the reading of the names of more than 6,000 people killed by gun violence since the tragedy in Newtown. The reading of names was expected to take 12 hours.

The commemoration was organized by Mayors Against Illegal Guns, a group founded by New York Mayor Michael Bloomberg. The group also launched a bus tour that will travel to 25 states over 100 days to build support for legislation to expand background checks for gun buyers.

Such legislation failed in the Senate in April, despite strong support from the Obama administration in reflection the deep divisions among Americans over gun control. While many citizens support stricter gun laws in the face of repeated mass shootings, others steadfastly argue firearms are a legitimate means of self-defense and are wary of any attempt to restrict buying and owning them.

The mayors group is also holding events in 10 states calling for lawmakers to expand background checks and urging senators who opposed the bill to reconsider.

The gunman in Newtown killed his mother and then the 26 people at Sandy Hook Elementary School with a semiautomatic rifle before committing suicide as police arrived.

Some of the victims’ families are in Washington this week lobbying lawmakers for action. Jillian and Carlee Soto met with President Barack Obama as they campaigned for gun control.

“He just told us to have faith,” said Jillian Soto, 24. “It isn’t something that happens overnight. It’s something that you have to continue to fight for. Within good time we will have this passed and we will have change.”

Mayor Bloomberg, one of the most powerful gun control proponents in the U.S., this week sent a letter asking donors not to support Democratic senators who opposed the bill to expand background checks.

On the other side of the debate, the National Rifle Association is focusing on Sen. Joe Manchin, A West Virginia Demcorat, who co-sponsored the bill to expand background checks, with a TV ad urging viewers to phone Manchin’s office and tell him “to honor his commitment to the 2nd Amendment” of the Constitution, which protects the right of citizens to own firearms. The NRA, the most powerful pro-gun lobby in the country, plans to spend $100,000 airing the ad in West Virginia markets over the next two weeks.