Who was the first player to have his number retired?

Lou Gehrig became the first player to have his number retired when the New York Yankees retired his #4, on Lou Gehrig Appreciation Day – July 4, 1939. The festivities of the day included, among other things, the reading of his famous “luckiest man on the face of the earth” speech. He was voted into the Hall of Fame that December, and died two years later from amyotrophic lateral sclerosis, now known as Lou Gehrig‘s Disease.