NEW YORK — Marvin Miller, the soft-spoken union head who led baseball players in a series of strikes and legal battles that won free agency, revolutionized sports and turned athletes into multimillionaires, died today. He was 95.

Miller died at his home in Manhattan at 5:30 a.m., said his daughter, Susan Miller. He had been diagnosed with liver cancer in August.

In his 16 years as executive director of the Major League Players Association, starting in 1966, Miller fought owners on many fronts, winning free agency for players in December 1975. He may best be remembered, however, as the man who made the word “strike” stand for something other than a pitched ball.

“All players — past, present and future — owe a debt of gratitude to Marvin, and his influence transcends baseball,” current union head Michael Weiner said. “Marvin, without question, is largely responsible for ushering in the modern era of sports, which has resulted in tremendous benefits to players, owners and fans of all sports.”