Beanies probably got their names from the slang term "bean," which meant head in the early days of the 20th century in the United States. The first beanies were almost like skullcaps and were used by blue-collar laborers who needed to keep their hair out of the way but did not want a brim that could obstruct their vision. Schoolchildren began to wear beanies in the early 1900s to imitate their working dads. The working beanies evolved into the modern-day baseball cap, but the children's beanies morphed into a hat that became hugely popular on U.S. college campuses around 1920. The beanies would have the school colors, the graduating year of the college student wearing it, or some other feature associated with the school. The addition of a small propeller to the top of the beanie made them a hit with kids. Eventually as college students and even children became more sophisticated, the beanie lost its following. However, it made a comeback in the woolen fleece version in the 1990s as cold-weather sports became popular.