Mayor Thomas Menino’s decision not to seek reelection, the death of her longtime husband, and a lengthy list of accomplishments during her tenure drove Superintendent Carol Johnson’s thinking about retirement, she said last week.

In an interview with the Reporter days after she made her decision, Johnson listed the overhaul of the city’s student assignment system, more K-8 schools, and a new contract with the teachers unions, among other items, as significant happenings during her six years as the city’s schools chief. She is expected to step down in July, at the end of the current school year.

“It’s not like we’re done,” she said. “But I think closing out this year seemed to be a good place to be.”

Johnson, who also served as schools chief in Minneapolis and Memphis, reflected on the death of her longtime husband Matthew, who died earlier this year after a long illness, and separately, she pointed to the bombings of the Boston Marathon on April 15. “I mean, obviously, the bombing is a reminder about how precious life is, and a reminder that every moment matters,” she said. “But I think I already felt some of that. When you’re married to somebody for almost 40 years, it’s a pretty significant, life-altering event, and so, [you’re] feeling like you really want to prioritize how you spend your time.”

Johnson was at the Boston Public Schools’ headquarters on Court Street when reports came in of the bombings, which killed three people, including an eight-year-old boy from Dorchester. After security guards told her they were locking down the building, she got into her car and received a text message from Michael O’Neill, the chairman of the School Committee: “Watch the news.”

Asked if she plans to stay in Boston, Johnson said she will likely be relocating. “I don’t expect to just sit around and do nothing. I’m not looking for another superintendent’s job, if that’s what you’re asking,” she said with a chuckle. “But I think there are a lot of ways to either volunteer or serve in public education that would be important to me. And so I don’t know for sure. I mean, I don’t have a job offer. And I think I’ve been pretty busy just trying to do my real job. So not a lot of time to think about what’s next. I’m not opposed to thinking about what’s next, it’s just I felt like I needed to tell the School Committee earlier rather than later.”

Menino’s announcement that he would not be seeking a sixth four-year term was also a factor for her. He often says that he is mayor of all of the city’s children, no matter where their parents send them to school, she said, and the school system has children who have a sibling in public, Catholic, and charter schools. “Our job is really to work together to make sure families have great choices,” Johnson said. “I think great cities have great public choices, great Catholic school choices, great religious school choices, and have greater charter school choices.”

Johnson pointed to the school system’s 66 percent graduation rate. “Every year, our graduation rates continue to go up across all racial and ethnic groups,” she said. “So I think that that is where the real work is and where we have to continue to persist in our efforts to create these opportunities that are engaging for students that meet their individual needs.”

Pressed for her thoughts on her own service, Johnson said, “I think that from a legacy standpoint, I think we made progress in taking schools that people had maybe given up on, and demonstrated that with the right interventions and support, with the right leadership, and sufficient data to look at who’s achieving, who’s not, really some analysis of that data in a much deeper way, I think that we’ve positioned the district to have high quality schools in every community.”

Johnson, who sometimes provoked controversy with some of her decisions, was also asked about regrets. “I think that, you know, there are always things we could’ve done better in terms of communicating to the public,” she said, adding that the school department did well in transparency with its data.

“I think we closed schools, we started new schools. I think we felt it was in the best interests of children, but you have to bring the community along, and sometimes, when you don’t, you’re sometimes back-tracking,” she said. “I mean, I’m human, so I make mistakes. And I think the most important thing is that we learn from the mistakes in ways that keep us from making them over and over again, and they drive us to create new policies and new ways of doing business.”

Asked about advice for her successor, Johnson said the next superintendent should also be a frequent presence in the schools. “Be in the community a lot. Because you learn when you listen,” she said.

The next person shouldn’t be afraid of making mistakes, either, she said. “I know I sometimes get beat up for making mistakes. I just don’t think you should be afraid of making mistakes and I don’t think you should be afraid of changing your mind, when you have made mistakes, and correcting them,” Johnson said. “I know that’s sometimes not the politically correct thing to do, but I feel like if you know you’ve made a mistake, acknowledge it, don’t blame other people, don’t blame down. Just take responsibility and move on, so that it can be better the next time.”