It was during Gene Upshaw's tenure as union chief that a new age of free agency and salary caps came to the NFL.
And with it came prosperity to both union members and owners.
For example, players are making close to 60% of the 32 teams' total revenues.
According to owners' figures, the players will be paid $4.5 billion this year.
The Robstown, Texas native's death Wednesday night at age 63 casts question marks around the upcoming contract talks between the NFL and its players.
The owners have decided to opt out of the collective bargaining agreement. That could mean a new round of labor strife in the NFL.
While some former NFL players have criticized Upshaw recently for their lack of benefits, most of those critics spoke well of him upon his passing.
And current NFL commissioner Roger Goodell said of the union boss: "Gene Upshaw did everything with great dignity, pride, and conviction."