In 2015, the U.S. Departments of Justice and Education released a Dear Colleagues Letter outlining civil rights obligations for ELLs. See below for additional information related to this topic.
https://legcounsel.house.gov/Comps/Elementary%20And%20Secondary%20Education%20Act%20Of%201965.pdf
https://www.migrationpolicy.org/sites/default/files/language_portal/chap15_0.pdf