On April 25, 2006, an initial group of 15 mayors, hosted by Boston Mayor Thomas Menino and New York Mayor Michael Bloomberg, held a summit at Gracie Mansion in New York City to discuss strategies for stopping the flow of illegal guns into America's cities. The mayors attending the summit drafted and signed a statement of principles to guide their efforts.

Mayors Against Illegal Guns is dedicated to making America's cities safer by cracking down on illegal guns. 30,000 Americans are killed every year as a result of gun violence, destroying families and harming communities. Mayors have a responsibility to protect their communities by holding gun offenders and irresponsible gun dealers accountable, demanding access to trace data that is critical to law enforcement efforts to combat illegal gun trafficking, and working with legislators to fix gaps, weaknesses and loopholes in the law that make it far too easy for criminals and other prohibited purchasers to get guns.

Since launching in 2006, the coalition's bipartisan ranks have grown to more than 450 mayors from more than 40 states, and the statement of principles has been endorsed by major national organizations such as the US Conference of Mayors and the National Conference of Black Mayors.