Thomas Menino’s influence didn’t stop at Boston’s city limits.When it wasn’t very popular to do so, Menino took risky stances on social issues, pushing for change first in Boston, and then nationwide.

He lobbied hard for the causes he believed in and convinced others to take action, and leaders across the country followed his example.

Menino didn’t have to be a national leader, but former Boston city council president Larry DiCara said he chose it.

“Whoever is mayor of Boston has the opportunity, when he walks into the room, people say my God, that’s the mayor of Boston. And he accepted that mantle and rose to leadership,” he said.

In that role, Menino declared prominently, again and again, that you can’t talk about crime in a big city without also talking about gun control, DiCara said.

“Some people will say it, some people shy away, Tom Menino never shied away," he said.

Menino did the opposite of shying away. He teamed with New York mayor Michael Bloomberg to found Mayors Against Illegal Guns, a group that now claims more than a thousand current and former mayors as members. Each has pledged to extend background checks and support legislation to target illegal guns.

Menino also led the nation’s mayors as president of the U.S. Conference of Mayors after 9/11. Tom Cochran is the group’s current executive director.

“After 9/11, we were all very much involved in securing our airports, etc. But he also said we must fight for those programs that will help our working poor. He was criticized somewhat for not going overboard with security, but he also said we must continue to not forget what’s needed for us to keep our great cities going,” Cochran said.

Others followed Menino’s lead because he was effective.

“When he spoke, people listened. And they realized that he was, as people have said, an urban mechanic. He knew how to get it done,” he said. Menino was called an urban mechanic for his attention to detail. MIT urban policy professor Phillip Clay said he took responsibility for getting even the smallest things done on the ground.

“His seriousness about doing things to make the city better right now, is a legacy that he leads. And the idea of the urban mechanic, I think, is going to be a key part of the role of a modern big city mayor," Clay said.

Clay said Menino didn’t worry about taking risky stances because he never really had to worry about being re-elected. So, Menino refused to march in St. Patrick's Day parades because organizers refused to admit gay people. He publicly rebuked the national restaurant chain Chik-fil-A for its support of anti-gay rights groups. And he started the first needle-exchange program in the country. That program changed the national conversation about AIDS, says Rebecca Haag, president of the AIDS Action Committee of Massachusetts.

"He recognized that if we could find a way to tackle HIV, then we would be better prepared as an urban area and a country to fight against other diseases,” Haag said.

Haag said when Massachusetts became the first state to legalize gay marriage, and Menino stood in city hall and welcomed the first gay couple to be married, he suddenly made it ok for other mayors across the country to do the same.

Nationally, Menino impacted things by creating here the kinds of programs and support and political statements that made Massachusetts a leader in HIV and AIDS as well as the LGBT movement. And also by choosing leaders and working with leaders locally who also then influenced the national scene.

Menino's influence touched many more spheres, he had a huge presence on climate change, speaking early on how urban areas should prepare.  He encouraged divestment from Arizona when that state cracked down on undocumented immigrants. He supported smoking bans.

Each time he took a stance, he made it easier for other leaders to move in the same direction. Not just here in Boston, but around the country.