There is a long history behind the first T-shirts and today’s colorful outerwear( 外套 ). Many stories talk about the first T-shirts and the reason why people wear them. One says the first T-shirts had something to do with war. In World War I Some American soldiers found that European soldiers’ undershirts( 汗衫 ) were cooler and more comfortable. They started to wear the same kind. Because the design of the undershirts was simple and looked like the letter T, Americans called the clothes T-shirts. By World War II Many soldiers started to wear T-shirts as underwear. In the 1930s Many American students started wearing white T-shirts for playing sport. In 1951 Marlon Brando, a very famous American actor, wore a tight-fitting( 紧身的 ) T-shirt in a film. After this, many American men started to dress like him. In the 1970s T-shirts became the favorite kind of clothing for young people in many countries. At that time, they were a sign of being cool and different from others. In the 1980s T-shirts started to be hot in China. Now many young people show their own ideas on their T-hirts: special pictures, funny words... T-shirts are more like artwork than just simple summer wear.