1916: The first baseball uniform numbers appear on the Cleveland Indians’ sleeves. But the idea doesn’t catch on and is dropped a year later.
1929: The Yankees become the first baseball team to put numbers on the backs of their jerseys. Within four years, all Major League teams have them.
1940: Dick Plasman of the Chicago Bears finishes his career as the last NFL player to play without a helmet.
1944: The Brooklyn Dodgers unveil a shiny satin uniform designed to be more visible during night games. The experiment flops and is quietly shelved until 1948, when it’s briefly revived by the Dodgers and the Boston Braves, and then is finally abandoned for good.
1945: NFL Commissioner Elmer Layden, concerned that football players have bad-looking legs, establishes a rule, still in place today, requiring all players to wear long stockings.
1959: Montreal Canadiens goaltender Jacques Plante is hit in the face by a shot, leaves to get stitches, and later returns to the game wearing the NHL’s first goalie mask.
1960: The Chicago White Sox becomes the first major sports team to put player surnames on the backs of their jerseys. Many teams in the new American Football League do likewise when the league debuts in the fall.
1963: Kansas City A’s owner Charles Finley, inspired by the rise of color television, outfits his team in green-and-gold uniforms, breaking baseball’s decades-long pattern of wearing white at home, gray on the road.
1970: The Pittsburgh Pirates become the first baseball team to abandon flannel unis in favor of form-hugging polyester double-knits. By 1973, every team has made the switch.
1976: The White Sox, in one of owner Bill Veeck’s classic stunts, take the field wearing Bermuda shorts.
1988: Clothier Alexander Julian designs purple-and-teal uniforms for the NBA’s expansion Charlotte Hornets. Over the next decade, purple and teal become the garish hues of choice for new teams throughout the sports world, as the Toronto Raptors, Vancouver Grizzlies, Florida Marlins, Colorado Rockies, Arizona Diamondbacks, Tampa Bay Devil Rays, Baltimore Ravens, Jacksonville Jaguars, Phoenix Coyotes, and San Jose Sharks all make their debuts wearing one or both of the colors.
1997: Cincinnati Reds outfielder Deion Sanders shortens his jersey sleeves as a tribute to Jackie Robinson. When league officials insist that Sanders’s sleeves match those of his teammates, the rest of the Reds opt to shorten their sleeves in solidarity.
1997: Craig McTavish, the last NHL player not to wear a helmet, retires.