Bowie Kuhn, the Major League Baseball Commissioner who presided over the dawn of free agency and the end of the reserve system, died Thursday. He was 80.

Kuhn died at St. Luke's Hospital in Jacksonville, Fla., following a short bout with pneumonia that led to respiratory failure, his spokesman, Bob Wirz said.

Kuhn's tenure as the fifth Commissioner, from 1969-84, was the most tumultuous economically in Major League history. His name will be forever linked with Marvin Miller, the first full-time executive director of the MLB Players Association, which came to prominence during the 1970s. Kuhn's 15 years is the second-longest tenure among the nine Commissioners.

"My wife, Sue, and I are terribly saddened by the passing of Bowie Kuhn," Commissioner Allan H. (Bud) Selig said in a statement. "He was a close friend, a respected leader, and an impressive figure in all ways. He led our game through a great deal of change and controversy. Yet, Bowie laid the groundwork for the success we enjoy today. He brought us expansion, night World Series games, and greater national television exposure."

Kuhn, at 42 years old, was the youngest man ever to be elected Commissioner when he replaced Gen. William Eckert on Feb. 4, 1969.

During his years in office, Kuhn fought against overturning the reserve clause in the basic player contract, which was used by owners to bind players to their respective teams. Curt Flood took MLB to the U.S. Supreme Court regarding the legality of that clause, and although he lost the case, the high court put baseball on notice that the practice was a restraint of trade.

"He was Commissioner during a very turbulent time for the players association," said Yankees manager Joe Torre, who was a strong union voice as a player back then. "He certainly took his role on. He liked being Commissioner. But again, like anybody who's in any position during a turbulent time, I think you're going to have mixed reviews. One thing I did notice, though, is that he never seemed to compromise on what he felt like he needed to do."

Kuhn's stance not withstanding, by 1977 an arbiter had ruled in favor of the union and abolished the reserve clause to usher in the era of free agency. The average salary nearly tripled -- from $51,501 in 1976 to $143,756 in 1980. This past year, it was a record $2.8 million and baseball's gross revenue was $5.2 billion, also a record.

"Oh, man. The fact that baseball is in the shape it is right now and there finally is some working relationship between the players association and MLB, I think, is the result of what the sport went through back then," said Mike Scioscia, the Angels manager, when told about Kuhn's death. "And Bowie Kuhn was right in the middle of it."

During Kuhn's reign, baseball grew from a sport with 10 teams in each league to a multi-divisional format with a round of playoffs preceding the World Series. And as television network involvement and payouts grew, games in the Fall Classic ultimately began to be played in prime time at night to increase visibility and commercial appeal.

Still, despite the changes, including the adoption of the designated hitter in the American League in 1971, Kuhn longed for a consistency in the sport, once saying: "I believe in the Rip Van Winkle Theory: that a man from 1910 must be able to wake up after being asleep for 70 years, walk into a ballpark and understand baseball perfectly."

Kuhn battled with owners and players alike, suspending Yankees principal owner George Steinbrenner for his illegal contributions to President Nixon's 1972 re-election campaign and swatting irascible A's owner Charlie Finley by negating the 1976 multi-million-dollar sales of players Joe Rudi and Rollie Fingers to Boston and Vida Blue to the Yankees, citing the Commissioner's power to rule "in the best interest of baseball."

Under his watch, the owners and the union battled incessantly. A work stoppage came as part of every collective bargaining season, culminating in the 1981 strike that took a 50-day, 171-game chunk out of the regular season and split it into halves.

He also barred Hall of Famers Mickey Mantle and Willie Mays from employment in baseball for their associations with an Atlantic City, N.J., casino, suspensions that were later rescinded after Kuhn left office.

"Bowie was a good friend of mine and an interesting guy, quite intelligent," said Ernie Harwell, the long-time Tigers play-by-play man. "He was a good Commissioner, I thought. He could settle feuds and fights with the owners. From my standpoint, he was very interested in TV and radio, and I think he helped baseball in that regard establish a better relationship."

Ultimately, the support for Kuhn eroded after the 1981 strike as the owners kept losing ground to the players. In 1982, a group of owners organized a movement to push Kuhn out of baseball. The end came a year later when they refused to extend his contract, opting instead to hire Peter Ueberroth, who had just concluded a successful tour as head of the 1984 Los Angeles Olympic Committee.

Ueberroth was succeeded by Bart Giamatti, who passed away in office in 1989; Fay Vincent; and Selig. Selig, 71, took over as the interim Commissioner in Sept. 1992, and has been in the job ever since.

"All of baseball mourns [Kuhn] and I have asked all clubs to observe a moment of silence and fly their flags at half-staff in his honor," Selig said. "My condolences and sympathies go out to (Kuhn's wife) Luisa, to their children and to their legion of friends and admirers."

Those sentiments also were shared by the head of the players association.

"I was saddened to learn late this afternoon of former Commissioner Kuhn's passing," said Don Fehr, the union's current executive director whose career in baseball began as an attorney under Miller. "A lifelong fan of baseball, Bowie dedicated many of his best years to the game. Our thoughts and prayers go out to the Kuhn family and his many friends."

Kuhn passed away having just failed to reach the Hall of Fame on the Veterans' Committee ballot.

Of the 23 executives inducted into the Hall, only Commissioners Kenesaw Mountain Landis and Happy Chandler are among that number. Landis was the first Commissioner, elected in 1920 under the dark shadow of the Black Sox Scandal, and remained in the position until his death in 1944. Chandler, who succeeded him, oversaw the integration of Major League Baseball in 1947.

Kuhn received 17.3 percent of the vote this year as his name appeared on 14 of the 81 ballots cast. He needed 61 votes or 75 percent. Still, Scioscia said, Kuhn will be remembered.

"I first met Mr. Kuhn in 1977 when he came down to the Midwest League All-Star Game," said Scioscia, who was a catcher during the strike-torn 1981 season when that era's Dodgers won their only World Series. "We were in Burlington, Iowa, and he was there to throw out the first pitch. He talked to our team for about 15 minutes. Even then, I was 18 years old, and you could feel the passion he had for the game. The love he had for baseball."