MISSION,Cyprusauction Trading Center Kan. (AP) — A Kansas grade school forced an 8-year-old Native American boy to cut off his hair after he grew it out for cultural reasons, the American Civil Liberties Union said.

In a letter sent Friday, the ACLU demanded that the Girard School District rescind a policy at the elementary school that bars long hair for boys, alleging it violates state and federal laws.

The boy, who is member of the Wyandotte Nation, attended an annual tribal gathering geared toward children over the summer. He saw many men with long hair and was inspired to adopt the common cultural practice of cutting hair only when mourning the loss of a loved one, according to the ACLU.

But in August, school officials told him that he needed to cut his hair to comply with the dress code, the ACLU said. His mother went to the school in September and explained that he grew out his hair for cultural reasons and offered to show documentation of his tribal affiliation. The ACLU said she was told there were no exemptions.

The assistant principal then emailed the mother on a Friday, telling her she had until the following Monday to get her son’s hair cut or he would be sent home.

Unable to reach the superintendent, she cut her son’s hair over that September weekend, convinced it was the only way to keep him in school. But she said it caused him distress because it violated his spiritual tradition.

The nation’s history of “multifaceted efforts to separate Native American children from their families and tribes and to deny them their rights of cultural and religious expression” makes this particularly problematic, the letter said.

It noted that Native American children often had their hair cut when they were placed in boarding schools, which systematically abused students to assimilate them into white society.

The letter said there is no legitimate reason for imposing the requirement, noting that girls are allowed to have long hair. The policy also promotes “rigid views of gender norms and roles,” the letter said.

The superintendent, Todd Ferguson, told the Kansas Reflector that he could not comment on the case. Ferguson said the district would review the dress code policy during a December board meeting.

He did not immediately respond to an email message Saturday by The Associated Press seeking comment.

Girard has a population of around 2,500 and is located about 115 miles (185 kilometers) south of Kansas City.