For N.F.L. players, federal court in Minneapolis is a legal nirvana.

Over nearly 40 years, cases filed there by players and their union have found favor in legal rulings by United States district court judges like Earl Larson and, since the late 1980s, David S. Doty. Names like John Mackey, Freeman McNeil, Marvin Powell and Reggie White have been featured plaintiffs.

And on Friday, when the N.F.L. Players Association decertified itself as a union, the Minneapolis court once again became the legal theater for football, this time in a particularly tense impasse. Ten players, including the star quarterbacks Tom Brady, Peyton Manning and Drew Brees, filed an antitrust lawsuit against the N.F.L. in the court and asked for an injunction to prevent the league from initiating a lockout, which the N.F.L. said was in effect as of 12:01 a.m. Saturday.

“The N.F.L. has a long history of violating federal antitrust law in an effort to minimize its labor costs,” the players’ lawsuit alleges about a subject that has become as familiar to the South Fourth Street Courthouse in downtown Minneapolis as First Amendment cases are to the Supreme Court in Washington.

But how did this Midwest court become the focal point for so many N.F.L. legal battles and, in effect, the home field for the players? The answer is apparently in a request that Mackey, the Baltimore Colts’ Hall of Fame tight end, made decades ago when he became the president of the players union in time for contract talks with the league.