Emanuel said there was a lot of "anguish" involved in making the decision but said the change will ultimately ensure a higher quality education for Chicago's children.
"The anguish and the pain...from making the change is less or minimal in my view or pales compared to the anguish that comes from trapping children in schools that are not succeeding," Emanuel said.
The plan would affect about 30,000 students and 1,000 teachers. CPS hopes the move will help close its $1 billion budget deficit, and projects annual savings of $43 million. Critics have complained the closures would disproportionately affect students in poorer areas where blacks and Hispanics live. The majority of the schools slated for closure are on the South and West sides.
Emanuel said closing all 54 schools at the same time was the right move, despite the backlash it caused from parents and the teachers union.
"I don't think anybody wanted to say, 'Well, it's very politically difficult, so therefore, we're going to lock a kid into a school for another year that's not achieving what it needs to achieve educationally," Emanuel said. "That's not right. That's not who Chicago is."
Speaking at an unrelated press conference in the city's Pullman neighborhood, Emanuel also said the total number of schools is not as important as the quality of education at those schools. He also tried to relieve concern over safety issues. Parents and teachers expressed concerns that consolidating schools will in some cases cause children to cross gang boundaries that may put them at risk.
Emanuel said the city is investing in increased security at schools. He said the city is doubling the budget for CPS's "safe passage" initiative and said it is also investing in things like more cameras around schools. Emanuel also noted CPS did not close any high schools due to safety concerns.
When asked about criticism coming from the Chicago Teachers Union - which has called the closings racist and dubbed Emanuel "the murder mayor" - he said he is focused only on improving the city's schools.
"I'm not interested in throwing terms around or schoolyard taunts," Emanuel said. "I'm interested in making sure the schools are achieving what they're set up to do."
Emanuel was also asked if announcing the closures while he was with his family on vacation was the best way to break the news. Emanuel responded by saying he was in contact with city officials throughout his trip.
"You're never far from the office," Emanuel said.