Built in 1908, the old gym was smaller than regulation, and its tan-and-white walls were covered with graffiti. The floor was slick, the hoops were the wrong size and the backboards were made of plywood, making it difficult for players to adjust to the Plexiglas ones used in games.
"There's not any bounce. It makes them throw it up there harder," Jackson said.
Jackson complained, and, he claims, was temporarily removed as coach for griping. He sued the Birmingham Board of Education under the landmark Title IX law, which bars discrimination in schools, but lower federal courts ruled against him.
Tuesday, the Supreme Court hears Jackson's case — a dispute asking whether Title IX protects people who blow the whistle on gender bias, regardless of their sex.
The Bush administration and a broad spectrum of civil rights groups are backing Jackson, while groups representing the school board and nine states are opposing him.
The Birmingham school board denies any discrimination and argues that Congress never meant for Title IX to cover people who say they suffered retaliation for reporting gender discrimination against others.
Jackson, 39, says he never thought so much would come of his concerns. "I've been in the system, I figured it'd be worked out," he said between classes. "But if you don't stand for something, you'll fall for anything."
And so he's become an unlikely champion of gender equity, traveling to Washington earlier this month to accept an award from the National Women's Law Center, which represents him in court.
He plans to attend the Supreme Court arguments, forcing him to miss a game for the first time in 18 years of volunteer and professional coaching.
He started work at Ensley High in 1999 and says the disparities between the girls and boys teams were soon clear.
Besides having to use the old gym, the girls sometimes rode to games in teachers' and parents' cars while the boys always used a bus, and the girls team didn't get any money from ticket or concession sales. Also, the school axed the girls' junior varsity team, while the JV boys kept playing.
"I thought it would get better," he said. "It didn't."
Jackson began pushing for changes, writing letters and meeting with school officials all the way up to a deputy superintendent. He said he was met mainly with indifference, and colleagues warned him about pushing the issue.
"They said, 'You better hush your mouth. You're making problems for yourself,'" Jackson said. "They weren't kidding."
Jackson said his job evaluations got worse, and he was removed as coach in May 2001, costing him nearly $7,000 annually in coaching pay. Because he had tenure, he kept teaching health and physical education.
Jackson sued under Title IX, claiming he lost the coaching position in retaliation for his complaints that the girls were victims of gender discrimination. A lower court threw out the case, agreeing with the board that the law doesn't cover retaliation claims.
The 11th Circuit Court of Appeals backed the lower court, but the Supreme Court accepted the case in June.
School board attorney Kenneth L. Thomas said he cannot discuss why Jackson was removed as coach, a position he since reclaimed. "That would just be inviting another lawsuit," he said.
The Bush administration has sided with Jackson, arguing that people who lacked legal protection would be less likely to complain about gender bias. A coalition of 180 groups including the NAACP, the American Jewish Congress, the American-Arab Anti-Discrimination Committee and the National Gay and Lesbian Task Force also filed a brief backing Jackson.
"As our Constitution recognizes in the First Amendment's protection of the rights of free expression and petition, the ability to exercise these rights unchilled by punishment is essential to the effective enforcement of all other rights," said the brief, filed by the Leadership Conference on Civil Rights.
Opponents, including the American Association of School Administrators, Alabama and eight other states, suggest Jackson could have sued under the First Amendment or other civil rights laws, but not Title IX.
"Teachers and coaches have plenty of protections if they feel like they are being retaliated against. They don't really need Title IX," said Naomi Gittins, senior staff attorney for the National School Boards Association.
No matter the legal outcome, Jackson said things have gotten better since he sued.
He was rehired as Ensley's girls coach on an interim basis last year, and the old gym has two new, regulation-sized hoops. The girls team now gets concession money, too.
But Jackson said his girls still usually have to practice in the chilly old gymnasium, and the boys are still in the nicer one.
"We don't want anything better than anyone else," Jackson said. "We just want the same."