By the 1920s, the T shirt had become an official world in American English and was included in the Merriam - webster Dictionary By World War II, both the U.S Navy and Army had in included the T -shirt as a standard piece of underwear.
Initially the T -shirt was worn exclusively as an undergarment , but that changed in the 1950s, The fame of the T -shirt skyrocketed when actors John Wayne ' Marlon Brando and Jane Dean wore their underwear on the big screen .In 1951 Marlon Brando caused a sensation in his film A streetcar Name Desire when his T -shirt was ripped off his body to reveal his naked chest . then James Dean made the T shirt a contemporary symbol of rebellious youth in the movie