Teach for America will add 4,000 teachers to nine cities over the next two years — including 286 in D.C. — thanks to a $20 million grant from the Walton Family Foundation announced Wednesday.

The foundation has also pledged a separate $4.3 million grant to Teach for America to train and support 1,000 teachers in the Mississippi Delta.

Teach For America is a national nonprofit program that recruits recent college graduates, gives them five weeks of training and sends them to mostly high-poverty public schools to teach for two years.

The Walton Family Foundation, created by the family that owns Walmart, is the largest private funder of Teach for America and has given the organization more than $100 million since 1993.

“TFA is doing a great job of recruiting highly talented, motivated people to teach in high need communities,” said Ed Kirby, deputy director of the foundation’s K-12 education reform efforts, adding that TFA recruits perform as well as veteran teachers. “The case to us is pretty compelling.”

The grant will pay for the recruitment, training and support for first- and second-year teachers. In the last school year, Teach for America placed about 5,800 teachers in classrooms around the country.

The Walton foundation is a strong backer of TFA because it has created a pipeline of education reformers, Kirby said. Two-thirds of TFA’s nearly 28,000 alumni work full-time in education, and more than 800 alumni serve as school principals or lead school systems. And many share the foundation’s enthusiasm for charter schools and the use of tax dollars to pay for private school tuition. Notable TFA alumni include former D.C. School Chancellor Michelle Rhee, who now runs StudentsFirst, and Mike Feinberg and Dave Levin, founders of the KIPP charter schools.

Teach for America has also received strong support from the Obama administration, winning a $50 million, four-year grant.

Teach for America has its opponents. Critics say Teach for America’s novice teachers are ill-prepared to lead the most demanding classrooms in the country, and that their two-year terms add to churn in schools that need stability. Teacher unions say TFA undercuts union jobs. Earlier this month, a group of TFA alumni organized the first national gathering of people opposed to Teach for America.

Last month, Gov. Mark Dayton (D-Minn.) vetoed a $1.5 million earmark that would have helped fund TFA in his state. Dayton said he didn’t see a need for the state to fund Teach for America, which reported $270 million in revenue and $350 million in assets in 2011.

In addition to D.C., the latest Walton grant will pay for TFA teachers in Denver, Detroit, Indianapolis, Los Angeles, Memphis, Milwaukee, New Orleans and Newark.