JACKSON, Miss. – The Mississippi school system that canceled a prom because a lesbian couple wanted to attend was sued today by the American Civil Liberties Union (ACLU).

The federal lawsuit, which seeks to force Itawamba County School System in Jackson to reschedule the prom, also accuses the school district of violating the First Amendment rights of Constance McMillen, the 18-year-old senior at Itawamba Agricultural High School who wanted to bring her girlfriend.

McMillen petitioned the school board to bring her girlfriend to the prom although district policy prohibited same-sex pairs as well as the male attire she desired to wear.

After hearing McMillen’s petition on Wednesday, the school board canceled the prom.

"Due to the distractions to the educational process caused by recent events, the Itawamba County School District has decided to not host a prom at Itawamba Agricultural High School this year," one school board member said.

"It's shameful and cowardly of the school district to have canceled the prom and to try to blame Constance, who's only standing up for herself," said Christine Sun, an attorney with the ACLU national LGBT Project.

"We will fight tooth and nail for the prom to be reinstated for all students."

As part of the school board’s decision, students were advised to throw their own private prom: "It is our hope that private citizens will organize an event for the juniors and seniors. We sincerely apologize for any inconvenience this causes anyone."

McMillen has voiced concern about the potential for backlash from other students regarding the loss of the prom.

"Oh, my God. That's really messed up because the message they are sending is that if they have to let gay people go to prom that they are not going to have one," she said. "A bunch of kids at school are really going to hate me for this."

McMillen is also worried about what this will mean for other gay students at her high school.

"A private prom would allow the district to get around the issue. If they set it up privately they probably aren't going to allow gay people to go and there is nothing that you can do about it," McMillen said.

"All I want is the same chance to enjoy my prom night like any other student. But my school would rather hurt all the students than treat everyone fairly," McMillen said in a prepared statement.

"This isn't just about me and my rights anymore — now I'm fighting for the opportunity of all the students at my school to have our prom."