The 59Fifty is a model of baseball cap made by the New Era Cap Company based in Buffalo, New York. They are often referred to as "Fitted Caps". The 59Fifty is the official on-field cap of Major League Baseball and Minor League Baseball, as well as the official sideline cap of the NFL as of 2012. 59Fifty caps are also made for the NHL and NBA. 59Fifty caps are available assorted "custom" colors for sports teams of the aforementioned leagues as well as city names and Marvel Comics and DC Comics character designs. Since its debut in 1954, the 59Fifty has become the standard American baseball cap, as well as a hat industry standard and fashion leader. These caps are distinguished by their high and stiff crowns.
New Era has been making caps for Major League Baseball since 1934, when they provided caps for the Cleveland Indians. Back then (and for several decades after) New Era had to compete with other companies, most of which were the leading sporting goods manufacturers of the time. The 59Fifty officially made its debut in 1954, but 59Fifty on-field caps were not available to the general public until 1978 when New Era placed a mail order advertisement in The Sporting News.
Changes to the 59Fifty over the next several decades were few, but there was some experimentation. During the 1970s and 80s, some teams experimented with nylon fabric as opposed to wool. Leather sweatbands fell out of favor to cloth sweatbands and were phased out by the late 80s. The underside of the visors were traditionally green, but beginning in the 70s, teams slowly switched over to gray. By 1995, all Major League Baseball teams were using gray. The New York Yankees were among the last teams to use green.
In the late 1980s, the suppliers for official MLB on-field caps were narrowed down to two; New Era and Sports Specialties. On-field caps then carried the "Diamond Collection" label from that point on. In 1992, MLB on-field caps began featuring the MLB "batterman" logo on the back of every cap. In 1994, New Era became the exclusive company to supply the official on-field caps of Major League Baseball. That same season, New Era provided bronze "batterman" pins for Major League Baseball's 125th anniversary that players pinned onto the back of their 59Fifty caps. In 1996, New Era began raising the embroidered logos on the 59Fifty. That year, film director Spike Lee requested the first 59Fifty cap that was not an official team color; a red New York Yankees cap. The New Era "flag" logo began appearing on the side of non-MLB on-field caps in 1997.
Beginning in the late 1990s, teams began to experiment with black fabric under the visors to help with the sun's glare, and black sweatbands to make them appear less sweat-stained. The "Diamond Collection" label also changed to the "Authentic Collection". In 2007, New Era changed the 59Fifty significantly. The material changed from wool to polyester, and all teams were now using black fabric under the visor as well as black sweatbands.
See also 
- "MLB celebrates new official cap." Major League Baseball. 14 March 2007.