Privately run charter schools in Chicago are benefitting from a record gift, even as Chicago Public School officials develop plans to shut down traditional schools.

The Walton Family Foundation today announced it invested a record $3.8 million in new Chicago charter schools—the largest amount given to any city in 2012.

The money was awarded throughout last year, and will cover the start-up costs for 13 schools.

Ed Kirby, the deputy director of the foundation’s education reform efforts, said Chicago is an important city in the charter school movement.

“We’re very confident in the city’s leadership, particularly the mayor to help expand and strengthen the charter sector in Chicago,” Kirby said.

The foundation, started by the owners of Wal-Mart and Sam’s Club, has given more than $22 million to new Chicago charter schools since 1997 and Mayor Rahm Emanuel has publicly advocated for charters as a way of improving the school system despite charters’ overall lackluster performance.

Teachers, parents and labor leaders have actively criticized charter schools, saying they push out hard-to-reach students.

School officials say closing schools is necessary to address next year’s budget shortfall, but they remain committed to opening new schools.