In many ways, the baseball cap is a symbol of the 20th century, as it became popular as the culture of sports increased in popularity, starting (naturally) with baseball. In 1860, the Brooklyn Excelsiors wore the ancestor of the modern, rounded-top baseball cap, and by 1900, the "Brooklyn style" cap became popular. During the 1940s, latex rubber became the stiffening material inside the hat and the modern baseball cap was born.
Baseball caps are made of all types of material and shaped in various styles for different purposes. Major league baseball players wear classic-style caps made of wool with their team's simple logo and colors; the logo is usually embroidered into the wool. Athletes in other sports wear caps with their team's logo and colors as "sideline" caps; both types are also sold as authenic team merchandise in retail stores and are quite popular. Farmers and migrant workers might be seen wearing plastic mesh caps with foam fronts with a farm feed supply company logo or the like printed on the cap. Other caps may simply have a company's logo, such as Nike or Carhartt; these hats are often made of brushed cotton. Golfers tend to prefer the visor form of cap which doesn't cover the head but keeps the sun out of their eyes; women also traditionally have worn visors casually but a trend towards certain youth subcultures see an increase in visor popularity among both sexes.
The baseball cap of the New York Yankees may be the most popular sports team cap and comes in many colors (other than the classic navy blue) and varieties. Major athletic cap manufacturers include Nike and New Era.