Constance McMillen, an 18-year-old senior at Itawamba Agricultural High School, reads her many messages from Facebook and MySpace concerning her desire to attend her senior prom with a same-sex date.

JACKSON, Miss. — A lesbian student who wanted to take her girlfriend to her senior prom is asking a federal judge to force her Mississippi school district to reinstate the dance it canceled rather than let the couple attend.

The American Civil Liberties Union of Mississippi on Thursday filed a lawsuit in U.S. District Court in Oxford on behalf of 18-year-old Constance McMillen, who said she faced some unhappy classmates after the Itawamba County School District said it wouldn't host the April 2 prom.

"Somebody said, 'Thanks for ruining my senior year."' McMillen said of her reluctant return Thursday to Itawamba Agricultural High School in Fulton.

The lawsuit seeks a court order for the school to hold the prom. It also asks that McMillen be allowed to escort her girlfriend, who also is a student at the school, and wear the tuxedo.

The district's decision Wednesday came after the ACLU demanded that officials change a policy banning same-sex prom dates because it said it violated students' rights. The ACLU said the district violated McMillen's free expression rights by not letting her wear a tux.

McMillen said she never expected the district to respond the way it did.

"A lot of people said that was going to happen, but I said, they had already spent too much money on the prom" to cancel it, she said.

McMillen said she didn't want to go back to Itawamba Agricultural High School in Fulton the morning after the decision, but her father told her she needed to face her classmates.

"My daddy told me that I needed to show them that I'm still proud of who I am," McMillen told The Associated Press in a telephone interview. "The fact that this will help people later on, that's what's helping me to go on."

The school board statement said it wouldn't host the event "due to the distractions to the educational process caused by recent events" but didn't mention McMillen. District officials didn't return calls seeking comment Thursday.

At least one supporter has offered to help McMillen and her classmates hold an alternate prom.

New Orleans hotel owner Sean Cummings told The Clarion-Ledger of Jackson he was so disappointed with the school board's decision he offered to transport the students in buses to the city and host a free prom at one of his properties.