The t-shirt or also known as the 'tee shirt' evolved from undergarments used in the 19th century. The one-piece "union suit" was cut into top and bottom and VOILA the t-shirt was created. It was named the T-Shirt due to the garment's outline. It was worn by miners and stevedores (longshoreman) during the late 1800's as a covering for hot environments. During WWI: American troops noticed European soldiers wearing lightweight cotton undershirts during hot and humid summer days. The undershirts quickly caught on with American Soldiers. By the 1920's the "T-SHIRT" had become an official word in the American Language and was included in Webster's Dictionary. By WWII both the Navy and Army included the T-Shirt as standard issue underwear.