The U.S. Department of Education required state departments of education to collect signed letters from their public school districts.

Walters had given district superintendents until April 25 to sign on to the letter, which was sent to all states by U.S. Education Secretary Linda McMahon. Every Oklahoma school district, more than 500 in total, had submitted signed letters by April 24, said Grace Kim, a spokesperson for Walters and the education agency.