When both Major League and Minor League Baseball teams take the field today, they'll be outfitted with red, white, and blue caps. Originally a gesture of patriotism, MLB teams began wearing small American flag patches on the left side of their caps on Independence Day, 2002. This would continue for six seasons, but in an effort to sell more merchandise, MLB and New Era created a series of flag-themed hats to be worn on the national holiday ever since.
The caps have slowly evolved since 2008, and we've compiled a year-by-year look at these patriotic hats below.
Every team was outfitted in a navy cap with a flag-themed logo, including the Toronto Blue Jays. Instead of the American flag, however, the Blue Jays wore a cap featuring a Canadian flag. The team still continues to do so present day, wearing the cap earlier in the week on Canada Day.
Looking to cover every color of the flag, the caps changed from navy to red the following year, and continued to use the previous year's team logos. As noted, the Blue Jays kept with the Canadian flag theme, looking more appropriate in all-red.
Finishing out the colors of the flag, teams wore white caps, but gave some teams red bills and some teams blue bills. There were no explanation as to why which team got which color brim, though.
A year later, teams used a throwback white front panel design. Again, some teams used blue crowns and brims, while others donned red crowns and brims with no explanation.
Completely switching themes, teams replace the flag-themed caps with camouflage logos. Keeping the team standard caps, the logos featured either a camo outline or filling.
Returning to the flag themed, teams wore white or gray caps, depending on whether they were playing on the road or at home. These caps, which featured New Era's "Diamond Era" technology, had red or blue bills.
This year, the caps are inverted from on another and grouped by leagues. American League teams will be wearing a red cap with a blue bill, while the National League will don blue caps with red bills. The hats feature white team logos placed on top of American flag-themed star.